Kind of interesting that McCain means "son of Cain".
Close, but no cigar:
elder son of Adam and Eve, from Heb. Qayin, lit. "created one," also "smith," from Sem. stem q-y-n "to form, to fashion." To raise Cain is first recorded 1840. Surnames McCain, McCann, etc., are a contraction of Ir. Mac Cathan "son of Cathan," from Celt. cathan, lit. "warrior," from cath "battle."
As a matter of interest, I learnt Welsh
at school, having some subjects taught partially in Welsh. The word for son in Welsh (and Cornish) is mab as in "Meibion Glyndwr" - "Sons of Glyndwr", the militant nationalist group - which becomes Ap in a Welsh patronym such as Ap-Myrddin. Similarly the word for head is ceann in Gaelic/Gallic (still used in slang by modern Scots to mean head/to know, written ken) and pen in Welsh. There are further examples and a discussion here
I don't mean to be a know-it-all, I just think it's good practice to jump on anything you see as untrue on this forum
Incredible, the gall of some of the bastards in these videos btw. They make quite chilling viewing.