The actual word Antichrist comes from the Greek antichristos (Strong's Concordance #G500) which means the opponent or adversary of the Messiah. It appears only five times in four Biblical verses, all of which occurs in books written by the Apostle John (1John 2:18, 22, 4:3 and 2John 1:7) between 63 and 64 A.D.
The Antichrist is also referred to by the Apostle Paul as the "man of sin," "the son of perdition," "the mystery of lawlessness" and "the lawless one" (2Thessalonians 2:3, 7 - 8). He is the "abomination of desolation," spoken of by Jesus, as someone who will stand in a newly constructed temple in Jerusalem (Matthew 24:15, Mark 13:14) and claim to be man's savior. He will then demand the right to be worshipped (2Thessalonians 2:4, Revelation 13:4, 8).
37. He will not regard the gods of his fathers, nor the desire of women . . . for he shall magnify himself above all (Daniel 11:37, HBFV)
According to the 1913 Catholic Encyclopedia, during the period of the Renaissance, Italian astrologers commonly believed that a conjunction of the planet Jupiter with the moon would signal the rise of this Satan-possessed human (article on Astrology). The Encyclopedia also goes on to speculate, in a different article, that this person might be a descendant of the Israelite tribe of Dan, which is the only one of thirteen tribes NOT listed in Revelation 7 (see Genesis 49:17, Jeremiah 8:16, Amos 8:14).
The numbers 13, 42, and 666 are closely associated with this person. The number thirteen symbolizes rebellious governments that are against God's ways, which will see its fullness in the end time one-world government that will oppose all that is good. This person's efforts to rule the world as a god will last 42 months or 1,260 days (Revelation 11:1 - 2). The identifying "number of the beast" (Revelation 13:8) or Antichrist, who will rule the earth, is 666.
The Antichrist, at the end of his forty-two month reign over the earth, will organize the largest military force the world has ever seen in order to fight against the Second Coming of Jesus Christ (Revelation 17, 19:19). He will be utterly defeated and consumed, however, in a place called Armageddon (Valley of Megiddo), by "the brightness of His (Christ's) coming" (2Thessalonians 2:8).