The Collaborative International Dictionary of English v.0.48:
Brood \Brood\ (br[=oo]d), n. [OE. brod, AS. br[=o]d; akin to D.
broed, OHG. bruot, G. brut, and also to G. br["u]he broth,
MHG. br["u]eje, and perh. to E. brawn, breath. Cf. Breed,
1. The young birds hatched at one time; a hatch; as, a brood
As a hen doth gather her brood under her wings.
A hen followed by a brood of ducks. --Spectator.
2. The young from the same dam, whether produced at the same
time or not; young children of the same mother, especially
if nearly of the same age; offspring; progeny; as, a woman
with a brood of children.
The lion roars and gluts his tawny brood.
3. That which is bred or produced; breed; species.
Flocks of the airy brood,
(Cranes, geese or long-necked swans). --Chapman.
4. (Mining) Heavy waste in tin and copper ores.
To sit on brood, to ponder. [Poetic] --Shak.