noun

• (uncountable) The young of any egg-laying creature, especially if produced at the same time.
• (countable, uncountable) The eggs and larvae of social insects such as bees, ants and some wasps, especially when gathered together in special brood chambers or combs within the colony.
• (countable, uncountable) The children in one family; offspring.
  "Ay, lord, she will become thy bed, I warrant, / And bring thee forth brave brood."
• (mining) Heavy waste in tin and copper ores.

adj

• (of animals) Kept or reared for breeding.
  "brood ducks"

verb

• (transitive) To keep an egg warm to make it hatch.
  "In some species of birds, both the mother and father brood the eggs."
• (transitive) To protect (something that is gradually maturing); to foster.
  "Under the rock was a midshipman fish, brooding a mass of eggs."
• (intransitive) (typically with over, on or about) To dwell upon moodily and at length, mainly alone.
  "He sat brooding about the upcoming battle, fearing the outcome."
• (intransitive) To be bred.