Breeder is a derogatory term for people who have children, particularly for parents who purportedly overfocus on their children and (allegedly) abandon their previous friends and lifestyle; or to women who give birth to many children, often with the derisive implication that they have "too many" offspring. The term is also used by antinatalists to pejoratively refer to anyone who has procreated, an act which they consider immoral. The phrases "breeder, not parent" (BNP) or "parent, not breeder" (PNB) are used by some childfree individuals to differentiate between what they regard as positive and negative parenting.
The use of "breeder" in this way is not new. It appears, for example, in Jonathan Swift's A Modest Proposal, widely acknowledged as the preeminent English satirical essay, in which Swift repeatedly uses the term.
The number of souls in this kingdom being usually reckoned one million and a half, of these I calculate there may be about two hundred thousand couple whose wives are breeders; from which number I subtract thirty thousand couples who are able to maintain their own children, although I apprehend there cannot be so many, under the present distresses of the kingdom; but this being granted, there will remain an hundred and seventy thousand breeders.
The term was part of a 2006 controversy in the heavily gay resort town of Provincetown, Massachusetts, when petitioners against same-sex marriage whose identity was published complained of having been called "breeders". The San Francisco Chronicle described the term as "a joking or derogatory slur used by gays to describe heterosexuals".