Antichrist

In some usages, refers to any person who attacks Christianity, such as the Roman Emperor Nero. In others, refers to the Beast 666 mentioned in the Revelation of John, aka the Book of Revelation or the Apocalypse.

Also used to refer to any person regarded as being exceedingly evil.

a quick search on "antichrist" in the king james version of the Bible reveals some things (see below), which make it sound to me like antichrist is an (idea), not a (person).

1John 2:18 Little children, it is the last time: and as ye have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
1John 2:22 Who is a liar but he that denieth that Jesus is the Christ? He is antichrist, that denieth the Father and the Son.
1John 4:3 And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.
2John 1:7 For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.

it's interesting to note the number of churches that tell you that there's this big evil antichrist dude, and he's completely indistinguishable from the real Christ.

another interesting thing is to compare the description of the "antichrist" in revelation to the catholic church.

Anti-Christ, anyone who denies the Father and the Son; or who will not confess that Jesus Christ is come in the flesh, or who, leaving the Church, pretends to be the Christ (or Messiah), and thus becomes the rival and enemy of Jesus, the true Christ.

Entry from Everybody's Cyclopedia, 1912.

An"ti*christ (#), n. [L. Antichristus, Gr. ; against + .]

A denier or opponent of Christ. Specif.: A great antagonist, person or power, expected to precede Christ's second coming.

© Webster 1913.