Greek: αρχαιος [archaios] (Adjective). Original, primeval, old, ancient.
αρχαιος [archaios] appears 12 times in the NT:
(1) Matthew 5: 21
Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: - τοις αρχαιοις [tois archaiois] Dat. pl. masc.
(2) [Matthew 5: 27]
Ye have heard that it was said by them of old time, Thou shalt not commit adultery: - τοις αρχαιοις [tois archaiois] Dat. pl. masc.
(3) Matthew 5: 33
Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: - τοις αρχαιοις [tois archaiois] Dat. pl. masc.
(4) Luke 9: 8
And of some, that Elias had appeared; and of others, that one of the old prophets was risen again. - των αρχαιων [tôn archaiôn] Gen. pl. masc.
(5) Luke 9: 19
They answering said, John the Baptist; but some [say], Elias; and others [say], that one of the old prophets is risen again. - των αρχαιων [tôn archaiôn] Gen. pl. masc.
(6) Acts 15: 7
And when there had been much disputing, Peter rose up, and said unto them, Men [and] brethren, ye know how that a good while ago* God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe. - αρχαιων [archaiôn] Gen. pl. fem. (*"a good while ago" - αφ ημερων αρχαιων [aph hêmerôn archaiôn] Lit: "from - days - ancients").
(7) Acts 15: 21
For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day. - αρχαιων [archaiôn] Gen. pl. fem. ("of old time" - εκ γενεων αρχαιων [ek geneôn archaiôn] Lit: "coming from generations ancient").
(8) Acts 21: 16
There went with us also [certain] of the disciples of Caesarea, and brought with them one Mnason of Cyprus, an old disciple, with whom we should lodge. - αρχαιω [archaiô] Dat. sing. masc.
(9) 2 Corinthians 5: 17
Therefore if any man [be] in Christ, [he is] a new creature: old things are passed away; behold, all things are become new. - τα αρχαια [ta archaia] Nom. pl. neuter.
(10) 2 Peter 2: 5
And spared not the old world, but saved Noah the eighth [person], a preacher of righteousness, bringing in the flood upon the world of the ungodly; - αρχαιου [archaiou] Gen. sing. masc.
(11) Revelation 12: 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. - ο αρχαιος [ho archaios] Nom. sing. masc.
(12) Revelation 20: 2
And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years, - ο αρχαιος [ho archaios] Nom. sing. masc. Variant: τον αρχαιον [ton archaion] Acus. sing. masc.