breed·er (brdr)
n.
1. A person who breeds animals or plants.
2. An animal kept to produce offspring.
3. Offensive Slang A heterosexual person.
4. A source or cause: social injustice
a breeder of revolutions.
5. A breeder reactor.
The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
It might also be worth checking out the variety of definitions at
urbandictionary.com
eg: Breeder is a slang term (either joking or derogatory) used to describe heterosexuals, primarily by homosexuals. It is drawn from the fact that while homosexual sex does not lead to reproduction, heterosexual sex can, with
implicit mocking by connotation of animal husbandry.