Brood

a number of young produced or hatched at one time; a family of offspring or young.
a breed, species, group, or kind:
The museum exhibited a brood of monumental sculptures.
to sit upon (eggs) to hatch, as a bird; incubate.
(of a bird) to warm, protect, or cover (young) with the wings or body.
to think or worry persistently or moodily about; ponder:
He brooded the problem.
to sit upon eggs to be hatched, as a bird.
to dwell on a subject or to meditate with morbid persistence (usually followed by over or on).
kept for breeding:
a brood hen.
brood above/over, to cover, loom, or seem to fill the atmosphere or scene:
The haunted house on the hill brooded above the village.
Contemporary Examples

‘True Detective,’ Obsessive-Compulsive Noir, and ‘Twin Peaks’ Jimmy So March 13, 2014
A Young Chef Travels to Calabria, Italy, and Learns the Old Ways of Cooking Curtis Stone November 27, 2013
Sorry About That, Cicadas Justin Green May 30, 2013
The New GOP Rock Star John Avlon December 10, 2008
Before the Fall: What Did the World Look Like in 1913? Jacob Heilbrunn June 8, 2013

Historical Examples

The Pacific Triangle Sydney Greenbie
Days Off Henry Van Dyke
Northern Nut Growers Association Report of the Proceedings at the Forty-Second Annual Meeting Northern Nut Growers Association
The Root of Evil Thomas Dixon
The Skipper and the Skipped Holman Day

noun
a number of young animals, esp birds, produced at one hatching
all the offspring in one family: often used jokingly or contemptuously
a group of a particular kind; breed
(as modifier) kept for breeding: a brood mare
verb
(of a bird)

to sit on or hatch (eggs)
(transitive) to cover (young birds) protectively with the wings

when intr, often foll by on, over or upon. to ponder morbidly or persistently
n.
v.