—v.t. 1. to produce (offspring); procreate; engender.
2. to produce by mating; propagate sexually; reproduce: Ten mice were bred in the laboratory. 3. Hort. a. to cause to reproduce by controlled pollination.
b. to improve by controlled pollination and selection.
4. to raise (cattle, sheep, etc.): He breeds longhorns on the ranch. 5. to cause or be the source of; engender; give rise to: Dirt breeds disease. Stagnant water breeds mosquitoes. 6. to develop by training or education; bring up; rear: He was born and bred a gentleman. 7. Energy.to produce more fissile nuclear fuel than is consumed in a reactor.
8. to impregnate; mate: Breed a strong mare with a fast stallion and hope for a Derby winner.
—v.i. 1. to produce offspring: Many animals breed in the spring. 2. to be engendered or produced; grow; develop: Bacteria will not breed in alcohol. 3. to cause the birth of young, as in raising stock.
4. to be pregnant.
—n. 1. Genetics.a relatively homogenous group of animals within a species, developed and maintained by humans.
2. lineage; stock; strain: She comes from a fine breed of people. 3. sort; kind; group: Scholars are a quiet breed. 4. Offensive.half-breed (def. 2).