That said, I do want to take up his comment that Genesis 6:1-4 "makes no reference to giants." I'm not so sure. The passage does refer to the Nephilim, and they are understood in Numbers 13:33 as "men of great stature" who made the spies of Canaan feel like grasshoppers.
Deane takes this meaning to be secondary, but it's hard to establish that. It depends on assumptions about which story is earlier, which is later, and our ability to determine how much the traditions were or were not mutually influential before they reached the form we have now. I have less confidence in such assumptions than I used to.
As far as I can tell, there was no specific word in ancient Hebrew for "giant." A giant was specified as someone of "great stature" or the like (Numbers 13:32-33; Deuteronomy 2:10, 21; 1 Samuel 17:4; 2 Samuel 21:24) or someone whose armor, weapon, or furniture was very big (Deuteronomy 3:11; 1 Samuel 17:5; 2 Samuel 21:19; 1 Chronicles 20:5). The Nephilim, the Anakim, and the Rephaim all seem to have been associated with extraordinary height.
Was the idea of great stature already inherent in the word "Nephilim" when Genesis used it? I don't know. We don't understand the etymology of the word and we only have two examples from which to establish usage. One specified great height and the other says nothing specific except that they were there at the time the story took place and afterward. But it seems entirely possible that great height was part of the meaning. In that case, the story does refer to giants.
By the way, an irrelevant but interesting detail: the words "Anak," "sons of the Nephilim," and "very great" (גדול מאד) are the ways to express the word "giant" according to the Alcalay Dictionary of Modern Hebrew. It also gives the word gigant, (גיגנט), clearly based on some form of the root of the word "gigantic."
UPDATE (9 January): Deane has replied to the above in a second update to his original post.
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