.]]A villain is an "evil" character in a story, whether an historical narrative or, especially, a work of fiction. The villain usually is the bad guy, the characters who fight against the hero. A female villain is sometimes called a villainess. Random House Unabridged Dictionary defines villain as "a cruelly malicious person who is involved in or devoted to wickedness or crime; scoundrel; or a character in a play, novel, or the like, who constitutes an important evil agency in the plot." Random House Unabridged Dictionary Web Result
Word origin
The etymology of the word is probably Middle English villein from Old French villain, in turn from Late Latin villanus, meaning serf or peasant, someone who is bound to the soil of a villa, which is to say, worked on the equivalent of a plantation in late Antiquity, in Italy or Gaul. Consequently, it meant a person of less than knightly status, and so came to mean a person who was not chivalrous; because many unchivalrous acts, such as tre
Source:
http://en.wikipedia.org/wiki/Villain