stud

A group of animals, especially horses, kept for breeding.

A male animal, such as a stallion, that is kept for breeding.

A stable or farm where these animals are kept.

A usually young man who is very sexually active or promiscuous.

A usually young man regarded as attractive and well-built.

A person who is extremely competent in a given area.

Stud poker.

(at stud) Available or offered for breeding. Used of animals.