villain Look up villain at Dictionary.com
c.1300, "base or low-born rustic," from Anglo-Fr. and O.Fr. villain, from M.L. villanus "farmhand," from L. villa "country house" (see villa).
"The most important phases of the sense development of this word may be summed up as follows: 'inhabitant of a farm; peasant; churl, boor; clown; miser; knave, scoundrel.' Today both Fr. vilain and Eng. villain are used only in a pejorative sense." [Klein]
Meaning "character in a novel, play, etc. whose evil motives or actions help drive the plot" is from 1822. Villainous is recorded from c.1300, from O.Fr. vileneus; villainy (early 13c.) is from O.Fr. vilanie.