Cainan in Fausset's Bible Dictionary

("possessor" or "weapon-maker"), as Tubal-cain comes from the Arabic "to forge" (Genesis 4:22). Son of Enos; aged 70 when he begat Mahalaleel; he lived 840 years more, and died at 910 (Genesis 5:9-14; 1 Chronicles 1:2). In Luke 3:36-37, second Cainan is introduced in the genealogy of Shem after the flood, a son of Cainan. A transcriber seems to have inserted it from the margin, where it was noted down from the Septuagint version of Genesis 10:24; Genesis 11:12; 1 Chronicles 1:18, but not in verse 24. For no Hebrew manuscript has it, nor the Samaritan Pentateuch, Chaldee, Syriac, and Vulgate versions from the Hebrew. Nor had even the Septuagint originally, according to Berosus, Polyhistor, Josephus, Philo, Theophilus of Antioch, Origen, Eusebius, Jerome. Beza's manuscript D, of Luke, omits it. Ephrem Syrus says the Chaldees in the time of Terah and Abraham worshipped a graven god, Cainan. The rabbis represented him as the introducer of idol worship and astrology.