antichrist

from WordNet (r) 3.0 (2006)

Antichrist
    n 1: (Christianity) the adversary of Christ (or Christianity)
         mentioned in the New Testament; the Antichrist will rule
         the world until overthrown by the Second Coming of Christ

from The Collaborative International Dictionary of English v.0.48

Antichrist \An"ti*christ\, n. [L. Antichristus, Gr. ?; 'anti`
   against + ?.]
   A denier or opponent of Christ. Specif.: A great antagonist,
   person or power, expected to precede Christ's second coming.
   [1913 Webster]

from Easton's 1897 Bible Dictionary

Antichrist
against Christ, or an opposition Christ, a rival Christ. The
word is used only by the apostle John. Referring to false
teachers, he says (1 John 2:18, 22; 4:3; 2 John 1:7), "Even now
are there many antichrists."

  (1.) This name has been applied to the "little horn" of the
"king of fierce countenance" (Dan. 7:24, 25; 8:23-25).

  (2.) It has been applied also to the "false Christs" spoken of
by our Lord (Matt. 24:5, 23, 24).

  (3.) To the "man of sin" described by Paul (2 Thess. 2:3, 4,
8-10).

  (4.) And to the "beast from the sea" (Rev. 13:1; 17:1-18).

from Hitchcock's Bible Names Dictionary (late 1800's)

Antichrist, an adversary to Christ