Antichrist: Greek word #500 antichristos (an-tee'-khris-tos); from #473 and #5547; an opponent of the Messiah: KJV-- antichrist.
Anti: Greek word #473 anti (an-tee'); a primary particle; opposite, i.e. instead or because of (rarely in addition to): KJV-- for, in the room of. Often used in composition to denote contrast, requital, substitution, correspondence, etc.
Christ: Greek word #5547 Christos (khris-tos'); from 5548; anointed, i.e. the Messiah, an epithet of Jesus: KJV-- Christ.
I think that that most people can agree that the one spoken of in the second half of Revelation chapter thirteen is the antichrist:
Rev 13:11-18
11 And I beheld another beast coming up out of the earth; and he had two horns like a lamb [he looked like Jesus Christ the true Lamb], and he spake as a dragon [because he is the dragon (one of satan's many names)].
12 And he exerciseth all the power of the first beast before him, and causeth the earth and them which dwell therein to worship the first beast, whose deadly wound was healed.
13 And he doeth great wonders, so that he maketh fire come down from heaven on the earth in the sight of men,
14 And deceiveth them that dwell on the earth by the means of those miracles which he had power to do in the sight of the beast; saying to them that dwell on the earth, that they should make an image to the beast, which had the wound by a sword, and did live.
15 And he had power to give life unto the image of the beast, that the image of the beast should both speak, and cause that as many as would not worship the image of the beast should be killed.
16 And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads:
17 And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.
18 Here is wisdom. Let him that hath understanding count the number of the beast: for it is the number of a man; and his number is Six hundred threescore and six. (KJV)
Let's see if we can find Scripture to further expound on just who this antichrist is. Let's go to chapter 12 of this book of Revelation. The below Scripture has not yet happened, St. John writes it as though it is past because he was taken to the future in the spirit and shown things that will happen in the end-times, many of them still future yet to us as the below Scripture is:
Rev 12:7-12
7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels
Here we see where satan is at the present time, he is in Heaven with God, but he is incarcerated and held in chains. Heaven is simply wherever God is. Don't be confused that satan is in the glorious eternity, which is written of in {Rev 21:1- on out}
8 And prevailed not; neither was their place found any more in heaven.
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
This is saying that satan (who goes by many many names, four of them given above in one Scripture even) is cast to earth with his angels. His (satan's) angels are the fallen angels, for they fall with satan as they also fell in {Gen 6:1-2}, and condemned in {Jude 1:6, and 2nd Pet 2:4}, and spoken of by Christ in {Mt 25:41}. These fallen angels are the locust army of {Rev 9:3}.
10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down [cast to earth. The " accuser" is another of satan's names (roles), for satan accuses us daily before the Lord] which accused them before our God day and night.
11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
12 Therefore rejoice, ye heavens, and ye that dwell in them [because satan is no longer in Heaven, he has been cast to earth physically, defacto! (in our near future this shall be fulfilled)]. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time [5 months (Rev 9:5 & 9:10)]. (KJV)
Here we saw that satan is cast down to the earth in the final times, and when he comes he has a short while, and he is wrathful to go about his task.
If this is not the antichrist from the first Scripture that we first looked at {Rev 13:11-18}, then where is this ''cast down one'' written of? Surely the Scriptures in the book of Revelation would not mention satan's arrival on earth and then be mute about what he does after he is cast down having great wrath (the Great Tribulation) would they?
Of course not, he is the antichrist (the beast) written of in our prior Scripture {Rev 13:11-18}. The one who looks like Jesus the Lamb: "and he had two horns like a lamb" {Rev 13:11}, the one who spoke like the dragon (satan/antichrist) because he was satan, he was the dragon: "and he spake as a dragon" {Rev 13:11}, the one with who has supernatural abilities: "And he doeth great wonders, so that he maketh fire come down from heaven on the earth in the sight of men, And deceiveth them that dwell on the earth by the means of those miracles which he had power to do in the sight of the beast" {Rev 13:13-14}, the one who controls the New World Order beast system from {Rev 13:1-3}: "And he exerciseth all the power of the first beast before him, and causeth the earth and them which dwell therein to worship the first beast, whose deadly wound was healed." {Rev 13:12}, the one who causes all to take the mark of the beast (spiritual mark, it is not a tattoo, computer chip...): "And he causeth all, both small and great, rich and poor, free and bond, to receive a mark in their right hand, or in their foreheads" {Rev 13:16}, the one who's number is: "and his number is Six hundred threescore and six" {Rev 13:18}.
Satan will come in the role of the antichrist.
2 Cor 11:13-15
13 For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ.
14 And no marvel; for Satan himself is transformed into an angel of light.
15 Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works. (KJV)
This word transformed is taken from a Greek word that means so much more. The Greek word 'metaschematizo'' is in the manuscripts, the King James Translators rendered it 'transformed.' Let's look at the truest definition of the word in the Strong's Exhaustive Concordance.
Transformed: Greek word #3345 metaschematizo (met-askh-ay-mat-id'-zo);from 3326 and a derivative of 4976; to transfigure or disguise; figuratively, to apply (by accommodation)
By this means he will in fact deceive the world, and none will even know to pray to God for deliverance because they will think He (God - Jesus -Messiah) is already here. That is why Jesus states: "Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh." (Matt 24:44). When does someone least expect the arrival of Christ? When they think that He is already here.
Hope this helps.