White is not just a colour. White light is the sum of all colours. Objects are perceived as what we call white when all visible light is reflected by the object.

The colour white is associated with purity, simplicity, safety and hope - positive qualities, in stark contrast to black. A room with white or pale coloured walls appears larger than one with dark walls. However, white also has connotations of weakness and lack of substance. It can be associated with fastidiousness and an excessive desire for tidiness and cleanliness. People of European descent are often referred to as white, although their skin colour is more accurately peach or beige. Animals, plants, birds and geographical features often have white in their name to denote their overall colouring or significant markings.

This A to Z covers just some of the current and old-fashioned occurrences of white in nomenclature.

A

• White arms are weapons which cut or pierce, as opposed to firearms. It is a translation of the French term armes blanche.

B

• The White Bird is the soul or conscience of man according to ancient belief. Islam contains the concept that the souls of the just lie under the throne of God until resurrection.

• Describing something as black and white implies either that it is written down and incontestable, or that the matter concerned is simple and clear cut with no middle ground.

• White bonnet is the term used for a person who makes bids at an auction merely in order to raise the price. This will be someone linked to the seller and will not be required to hand over any money if there are no higher bids. Other nicknames for someone doing this are puffers, by-bidders, cappers, and decoy ducks. In the UK at least, there are now laws to restrict this practice.

• A whiteboard is a panel, either fixed to a wall or on a stand, upon which one can write with non-permanent marker pens and clean markings off using a dry cloth. Whiteboards can also be used as a screen for projected images. The surface is usually shiny vinyl or polyester and the support board may be chipboard, hardboard or a similar material. These boards became popular in schools and offices in the 1990s as an alternative to blackboards. A further development has been the interactive whiteboard or 'SMART board' which is touch sensitive. The output from a computer can be projected onto the screen and manipulated via the screen.

C

• White charcoal differs from black charcoal in the manufacturing process in the temperature used and the cooling process. For black charcoal, wood is carbonised at a temperature of 400–700°C then cooled slowly. White charcoal is carbonised at a lower temperature until near the end of the process, when the temperature is raised to 1,000°C. A powder of sand, earth and ash is used to cool the charcoal quickly. This produces a much harder material with a clean, smooth surface which is a light grey colour, rather than being actually white. It is used in electronics and has medical applications.

• White clothing indicates cleanliness, purity, wisdom and sometimes authority. In the past, only the wealthy would wear white clothing as it was expensive to produce and difficult to keep clean and in Elizabethan times, there were laws dictating who could wear white, according to their status. Doctors and similar professionals used to wear white coats although in many workplaces this has been discontinued as thought to hamper rather than aid infection control. Laboratory worker still wear white coats for protection against spills and stains. White clothing is associated with angels, deities, fictional heroes and 'goodies' (as opposed to 'baddies'), brides and often in sporting events.

• White Coal is a name for water when used for power such as a water wheel or in hydroelectricity. This term is also used for fuel made by drying wood over an open fire.

• A white collar worker is someone who works at a desk in an office as opposed to being a blue collar worker, someone doing manual labour or operating machinery. Historically this literally did refer to the colour of the shirts worn by each type of worker.

D

• White damp is the name used in the mining industry for the gas carbon monoxide. It may be present after a gas or coal dust explosion or after a fire in a mine and is highly poisonous. It is colourless, odourless and tasteless.

• A White Dove is a symbol of holiness and peace. In Christian art, it is used to represent the Holy Ghost, also the soul, especially that of saints. The story of Noah in the Bible tells of the release of a dove from the Ark which returns with an olive branch in its beak showing that the flood is subsiding and land is nearby. The white dove is also a symbol of love and fidelity, often used in association with Valentine's Day and Wedding celebrations. This is probably because doves mate for life, display much affection for each other and share care of their young. In Ancient Greece and Rome, doves were given to the bride by the groom. For many years in the past, doves were released at a wedding. This still happens at some weddings today but these birds are usually white homing pigeons (Columba livia) rather than true doves (Streptopelia risoria).

• A white dwarf is the core of a star after all the outer layers have burned away and all the fuel is gone. It become small, dense and extremely hot. It shines in the same way that a piece of iron in the blacksmith's fire glows white, because of its extreme heat. A typical white dwarf is slightly larger than the Earth but 200,000 times more dense. The temperature drops gradually, taking about a billion years.

E

• Ecclesiastical robes are white for specific events, to denote purity. In the Christian church, white is worn by the priest for Christmas, Easter, Ascension Day and some Saints' festivals. Traditionally white is worn by those being baptised, as well as by those being ordained. Originally people were baptised naked and dressed in a simple white tunic after the ceremony.

• The Egyptians depicted the god Osiris with a white crown. The Pharaoh wore a white crown to demonstrate his superiority.

• A white elephant is a rare but usually unwanted object. The white elephant stall at fundraising fetes and bazaars is often a repository for unwanted gifts and useless bric-a-brac. The term originates from Asian countries where white elephants were revered and led a pampered life. The gift of a white elephant therefore imposed great expense on the recipient.

• The White Ensign, also known as St George's Ensign, is a flag used by the Royal Navy and Royal Yacht Squadron. It comprises the St George's red cross on a white background, with the Union Jack in the first (top left) quadrant.

F

• A white feather is a sign of cowardice, frequently given during World War I by young women to men who had not volunteered to fight. The origin is in cockfighting, where a white feather in a gamecock's tail indicates that it is not of true stock, but of inferior breeding.

• A white flag is used to signal surrender or a truce for unarmed parley.

G

• In many board games between two people, one set of pieces is white and the other, black. In chess, white always makes the first move.

• In Geography many place names reflect their notable colour, such as the White Cliffs of Dover. This is often a result of widespread chalk in the area.

• White about the gills is an expression meaning that someone appears terrified or ill with facial pallor because blood circulation has been prioritised elsewhere in the body. Alternative expressions for this are as white as a sheet or as white as a ghost.

• The Great White Way is an early name for Broadway in New York City because of the many electrically lit advertising signs.

• The Ancient Greeks used to wear white nightclothes as they believed this would help them sleep well and have pleasant dreams.

H

• In heraldry, historically white was interchangeable with argent (silver) and was even used to represent light blue and grey, before silver thread or paint was readily available. In modern heraldry white is used in its own right as a separate colour, denoting ermine.

• To Hit the White is to make a good shot, to be absolutely right. This derives from archery, when in the past, white was the colour of the innermost circle of the target.

• White hot describes the intense temperature at which a substance glows white. White hot can also be used to describe a state of intense, frenetic activity.

I

• White ink is usually made with titanium oxide. In many printing instances white is achieved simply by using white paper and coloured ink to define the boundaries of the white area. Printing inks are usually translucent to some degree and several layers of white would be needed to obscure a coloured base. There are suitable white inks that can be used for screen printing, or foils that be used to create the appearance of white.

J

• A white jigsaw has no picture - all the pieces are blank white. The pieces are all different shapes. With only a small number of pieces such a puzzle is relatively easy to complete. The difficulty increases with the number of pieces.

K

• A white knight is someone considered noble and good, coming to one's rescue, possibly putting themselves at risk. They may prefer anonymity.

• A white knuckle ride is a thrilling but frightening experience. This stems from the likelihood of tightening ones knuckles in a fist or gripping an object in this position, which would have the effect of making the knuckles appear white.

L

• A white lie is an untruth but one told out of kindness or intended to be a harmless deceit.

• White lightning is illegal whiskey or moonshine.

M

• White magic is generally thought of as being good, beneficial magic as opposed to black magic. Strictly speaking it is magic which does not involve invoking the devil.

• White is the colour for mourning in China, the Middle East and Ethiopia and is worn by Hindus for a funeral. In India, widows wear white. In Japan white carnations are used at funerals although the bereaved wear dark clothing. Medieval European Queens also wore white for mourning.

N

• A white night is a term for a sleepless night, or a Summer night in those latitudes where it never becomes dark.

• White noise is a combination of all the different frequencies of audible sound at equal power. This sound can be used to mask unwanted noise which becomes lost amongst the other frequencies.

O

• Whiteout is zero visibility, such as in a heavy snowstorm or after snowfall has rendered both sky and ground white so that it is difficult to distinguish any geographical features or familiar landmarks. A similar effect can arise with low lying cloud or fog, reducing visibility to maybe a few metres at best.

P

• White paint or colouring was probably originally made from chalk, lime dust. The earliest made pigment used lead and this continued through to the 19th Century when manufacture was restricted because of its toxicity. Zinc oxide, known as Chinese white, was used for watercolour paint from the 18th Century, but was not available as an oil paint until the 19th Century. It is slow drying compared with lead-based paint, but cheaper and non-toxic. However, it becomes brittle over time. Titanium dioxide, which was discovered in 1821, came into use as a white oil colour in the 1920s and is most widely used today.

• White papers are documents produced by the Government, setting out policy details on a particular subject. A White Paper allows the Government an opportunity to obtain feedback before formally presenting the policy as a Bill.

Q

• The White Queen is a character in Lewis Carroll's Through the Looking Glass where the action takes place loosely on the layout of a chess board. The White Queen appears very dishevelled and during conversation with Alice declares that she has believed as many as six impossible things before breakfast. Mary Queen of Scots was known as the White Queen because of the white clothes she wore in mourning for her husband, Francis II of France.

R

• A White Russian is an inhabitant of White Russia, now Belarus. It is also a term for members of the White Army at the time of the Bolshevik revolution, in contrast to the Communist Red Army.

  White Russian is also a cocktail. It is a Black Russian, a mixture of vodka and coffee liqueur but with the addition of milk or cream.

S

• White satin is an old nickname for gin.

• Snow White is the heroine of a German folktale, made famous by the Brothers Grimm. She was brought to a wider audience by Disney in the animation 'Snow White and the Seven Dwarfs'. Her name derives from her extremely pale skin.

• White spirit is a colourless, transparent liquid derived from paraffin, used as to thin oil-based paints and to clean paintbrushes. It has also been used as a dry cleaning solvent. It is a mixture of hydrocarbons.

• A white stick denotes that the carrier is blind or has poor sight. This may be simply an ordinary walking stick painted white or a collapsible aluminium cane. These are of different types, to be used either as a symbol, or as a walking guide.

• A white squall is a sudden, violent storm that occurs at sea, featuring white-topped waves but an absence of dark clouds.

• Whit Sunday, originally White Sunday, is the seventh Sunday after Easter in the Christian calendar, marking the descent of the Holy Ghost on the day of Pentecost. It used to be a very popular date for baptisms for which candidates wore white garments, giving the date its name.

T

• A white tie event is a very formal one, requiring men to wear a white bow tie, wing collar shirt and waistcoat, with a black tail coat and trousers. A black top hat is included if out of doors. Women would wear a long evening dress and jewellery.

U

• The unicorn is a mythical and heraldic white beast. Images of a single-horned horse-like creature date from ancient Babylon. The earliest written description is by a Greek physician, Ctesias, around 400 BC. Based on accounts of travellers, he records the existence of a horned wild ass living in India. In the Middle Ages it was depicted as having the head and body of a horse, the tail of a lion, the legs of a buck and a single horn in the centre of its forehead. Many legends have evolved worldwide concerning the character and magical powers of the unicorn. A unicorn features with a lion in the United Kingdom's royal coat of arms, as supporters of the shield.

• White uniforms are worn in many spheres. School uniform often includes a white shirt. Pilots and the British police also wear white shirts as part of their uniform. The UK's Royal Navy and other military bodies have a white uniform for specific occasions or for hot climates. Nurses used to wear white dresses or aprons and headdresses based on nun's attire, but now it is more usual for them to wear dresses or tunic and trousers of a colour which denotes their status.

V

• White van man is the term for the stereotype of a driver of a commercial vehicle such as a Ford Transit, usually coloured white. The driver is often a self-employed handyman or tradesman and renowned for his aggressive, poor standard of driving.

W

• Wedding dresses in the Western World are usually white. Historically, ordinary people wore their best clothes to be married, which might be any colour. The wealthy would opt for sumptuous fabrics using expensive dyes such as red and purple. There is some controversy as to whether or not white was popular to symbolise purity. Queen Victoria wore a white dress for her wedding and this set a new trend for the UK. By the 1890s, clothing had become more affordable so that more brides could consider having a new dress specifically for their wedding. In the East, red is more usual for the bride. In Japan white is the colour for mourning flowers; a bride wears a white kimono symbolising death, the bride leaving her family, then being reborn in her new family.

• Someone described as whiter than white is deemed to be totally honest and incorruptible.

• Whitewash is a thin paint made from lime and water, used to cover a poor surface in preparation for decorating. It is also a term for concealing shabby practice or poor workmanship.

• Some animals that live in northern areas where snow is prolonged during the winter have a winter coat, that is, they grow a white coat of fur, hair or feathers ready for camouflage against the snow. The trigger for this change is the lowering temperature and reduction in daylight hours. As spring approaches and the snow melts, they return to their summer colouring. Such animals include the arctic hare, arctic fox, ptarmigan, lemming, caribou and stoat.

X

• A White Xmas is the term for snow at Christmas, either falling on the day or already carpeting the ground. Such scenes are popular on Christmas cards and in stories. Each year, many people place bets on whether or not snow will fall on Christmas Day.

Y

• The white Yajur Veda is a Hindu scripture. It concentrates on liturgy as opposed to the black Yajur Veda which is concerned with ritual. Together they comprise one of the four Vedas which are the primary texts of Hinduism. The others are the Rig Veda, the Sama Veda and the Altharva Veda.

Z

• A white zebra is not plain white, but has very light brown colour stripes and blue eyes because of amelanosis, a lack of the pigment melanin. These animals are extremely rare. Animals may have albinisim, a complete lack of pigments giving rise to an appearance of pink eyes and white hair, fur, feathers and skin.