giblets: [14] French gibier means ‘game’ – in the sense ‘hunted animals’ (it comes from Frankish *gabaiti ‘hunting with falcons’). In the Old French period this seems to have produced a diminutive form *giberet, literally ‘small game’, which, though never recorded, is assumed to have been the basis of Old French gibelet (l and r are very close phonetically, and each is easily substituted for the other). Gibelet is only known in the sense ‘game stew’, but it seems quite plausible that it could have originally meant ‘entrails of hunted animals’ (Walloon, the French dialect of southern Belgium, has giblè d’awe ‘goose giblets’).
"edible entrails of a fowl, parts removed or trimmed from a fowl when it is prepared for roasting," mid-15c. (in singular, gybelet), earlier "unnecessary appendage" (c. 1300), from Old French gibelet "game stew," a cookery word of uncertain origin; perhaps from Frankish *gabaiti "hunting with falcons," related to Old High German beizan "to fly a falcon," literally "to cause to bite," from bizzan "to bite."