Why was "tantrum" trending last week?
1640s, "hovering, overhanging" (as a mother bird does her nest), from present participle of brood (v.); meaning "that dwells moodily" first attested 1818 (in "Frankenstein").
"action of incubating," c.1400, verbal noun from brood (v.). Figuratively (of weather, etc.) from 1805; of mental fixations by 1873. Related: Broodingly.
Old English brod "brood, fetus, hatchling," from Proto-Germanic *brod (cf. Middle Dutch broet, Old High German bruot, German Brut "brood"), literally "that which is hatched by heat," from *bro- "to warm, heat," from PIE *bhre- "burn, heat, incubate," from root *bhreue- "to boil, bubble, effervesce, burn" (see brew (v.)).