From The Collaborative International Dictionary of English v.0.48:
Brood \Brood\, a. 1. Sitting or inclined to sit on eggs. [1913 Webster]
2. Kept for breeding from; as, a brood mare; brood stock; having young; as, a brood sow. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Brood \Brood\ (br[=o]ch), v. i. [imp. & p. p. Brooded; p. pr. & vb. n. Brooding.] 1. To sit on and cover eggs, as a fowl, for the purpose of warming them and hatching the young; or to sit over and cover young, as a hen her chickens, in order to warm and protect them; hence, to sit quietly, as if brooding. [1913 Webster]
Birds of calm sir brooding on the charmed wave. --Milton. [1913 Webster]
2. To have the mind dwell continuously or moodily on a subject; to think long and anxiously; to be in a state of gloomy, serious thought; -- usually followed by over or on; as, to brood over misfortunes. [1913 Webster]
Brooding on unprofitable gold. --Dryden. [1913 Webster]
Brooding over all these matters, the mother felt like one who has evoked a spirit. --Hawthorne. [1913 Webster]
When with downcast eyes we muse and brood. --Tennyson. [1913 Webster]
From 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, v. t.] 1. The young birds hatched at one time; a hatch; as, a brood of chickens. [1913 Webster]
As a hen doth gather her brood under her wings. --Luke xiii. 34. [1913 Webster]
A hen followed by a brood of ducks. --Spectator. [1913 Webster]
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. [1913 Webster]
The lion roars and gluts his tawny brood. --Wordsworth. [1913 Webster]
3. That which is bred or produced; breed; species. [1913 Webster]
Flocks of the airy brood, (Cranes, geese or long-necked swans). --Chapman. [1913 Webster]
4. (Mining) Heavy waste in tin and copper ores. [1913 Webster]
To sit on brood, to ponder. [Poetic] --Shak. [1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Brood \Brood\ (br[=oo]d), v. t. 1. To sit over, cover, and cherish; as, a hen broods her chickens. [1913 Webster]
2. To cherish with care. [R.] [1913 Webster]
3. To think anxiously or moodily upon. [1913 Webster]
You'll sit and brood your sorrows on a throne. --Dryden. [1913 Webster]