But there is also ent, which appears several times in OE poetry as eald enta geweorc, a comment upon the massive Roman stonework encountered by the Anglo-Saxons in their new home. Wondringly, they called it “the work of giants of old.” This is the word taken up by J.R.R. Tolkien and given a new, woodsy twist when “Giant Treebeard” was reimagined as one of the shepherds of the trees.
Then there is þyrs, an elusive word for something of giant-kind, though perhaps not so large. Grendel, the foe of Beowulf, is a þyrs. The word can be translated “ogre,” perhaps “troll.” It was frequently used in compounds, as in orcþyrs. In Middle English, we see “hobthrush,” with the hob- element of “hobgoblin” attached to thurs/thrush. At this point, it has dwindled to something like "bogey."
Upon contact with Scripture and Latin, OE authors began to pick up gigant and finally, on the cusp of Middle English, geant. The author of Beowulf uses this word only to refer to the giants of Genesis cap. VI. He seems to be making a distinction between the giants of Scripture and the giants of native folklore.
How interesting, then, to read the OE Genesis and find the standard OE translation of Gen. 6:4 begin, Entas wæron eac swylce ofer eorðan on ðam dagum . . . (“There were giants on the earth in those days . . .”). The Beowulf poet is making a personal distinction for artistic effect, then, not making a point about proper labeling of supernatural beings as understood by the run of OE authors.