O.E. bredan "bring young to birth, carry," also "cherish, keep warm," from W.Gmc. *brodjan (cf. O.H.G. bruoten, Ger. brüten "to brood, hatch"), from *brod- "fetus, hatchling," from PIE *bhreue- "burn, heat" (see brood). Original notion of the word was incubation, warming to hatch. Breeding "good manners" is from 1590s.