Definitions of breed:

• noun:   a lineage or race of people
• noun:   a special variety of domesticated animals within a species

  Example: "He experimented on a particular breed of white rats"

• noun:   a special lineage

  Example: "A breed of Americans"

• noun:   half-caste offspring of parents of different races (especially of white and Indian parents)
• verb:   have young (animals)

  Example: "Pandas rarely breed in captivity"

• verb:   of plants or animals

  Example: "She breeds dogs"

• verb:   copulate with a female, used especially of horses
• verb:   call forth
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #9154)