Linguists tell us there are two aspects to a word. Take the word 'dog', for example. First, there is the form of the word. This is its sound image, simply what you hear when someone next to you says 'dog'. Then, there is its meaning - the concept of a four-legged animal covered in fur that pops up in your head when someone next to you says 'dog'. These two aspects are usually referred to as signifiant and signifié, because the man who thought all this up, Ferdinand de Saussure, was Swiss. Some linguists insert a third component to this system - the referent - ie the real dog who is looking up at you wagging its tail.

Now the interesting thing about these two aspects, the linguists continue, is that the relation between signifiant and signifié is completely arbitrary. In other words, there is no reason whatsoever why a dog is called 'dog'. Many words' origins can be traced very far back in time - some as far back as the original Indo-european language - but this doesn't give us a clue about why things are called what they are. Thus, the signifiant for the concept 'dog' might just as well be 'table', or 'anchorman', or 'stinker', if this were social convention. But, interrupt the non-linguists, there are lots of words whose form and meaning are related! Indeed, there is a whole group of words which are formed in a reasonably close imitation of a sound that is associated with their concept - to put it more simply, they sound like the noise they're describing. These words are called onomatopoeia (the adjective being onomatopoeic). If you say that dogs 'bark', you are using an onomatopoeic word. If you say that a tree is covered in 'bark', you are not.

Naturally, onomatopoeia only occur in certain fields of the lexicon. You will find a high proportion of them in verbs and nouns that are related with, or indeed describe, a certain sound. Examples are 'to crash', 'to bang', 'to whistle', 'to mutter'. Words related to animals are very often onomatopoeic. Think of 'to meow' 'to whinny', or 'the cuckoo'.

Onomatopoeia also are an important device for cartoons, where they usually appear as injections such as 'splat' or 'boom'. When referring to literature, especially to poetry, the term 'onomatopoeia' is also frequently used, though in a much wider sense; it is a stylistic device 'by which sound is used to communicate sense' ¹. Thus, such words as 'uffish', or 'galumphing', or 'mimsy' in Lewis Carroll's Jabberwocky might be considered onomatopoeic - they may not really describe a sound, but they evoke a certain atmosphere and thus bear sense. De Saussure recognised the existence of onomatopoeia; however, he did not see them as a threat to his theory. Some of his arguments were:

• They only constitute a tiny part of the lexicon.

• In the course of time, they undergo fundamental changes, thus becoming abstract symbols as well. For example, the word 'pigeon' was originally derived from the Latin onomatopoeic pipio.

• They are not universal - 'cock-a-doodle-doo' is cocérico in French and kikeriki in German.

This proves that onomatopoeia are just convention after all. Many words that appear to be onomatopoeic actually are not, but were derived from completely different words - for example, 'to whip' can be traced back to Latin vibrare and Sanskrit vepate ('he trembles').