Besides being an adjective meaning covered in fine hair, "Furry" has a number of
additional uses as a noun:

A furry is an anthropomorphic animal, that is an animal having some of the characteristics
of a human like being able to walk on two legs, speak human languages, use tools etc.
Many cartoon characters are furries: Mickey Mouse, Bugs Bunny, and they make frequent
appearances in childrens literature such as the works of Beatrix Potter. They are not just
a recent phenomenon either: furries also appear in Shakespeare and Aesops fables, and
in darker works like Dr. Moreau, Animal farm, and every werewolf novel written.

Fans of furry art & literature often refer to themselves as furries too. Online they typically
assume furry identites, and have furry characters on roleplaying systems like MUDs/MUCKs.
For some of these furries there is a deeper connection that goes beyond appreciation of
artwork and stories. This can include concepts such as totemism and spritual theriantropy.
Whatever fuels their fascination with these animal-human hybrids, furries often have
social gatherings - sharing stories, ideas, and art and generally having fun. If you see
people with the occasional tail, animal ears, or full "fursuit" they may be furries.