- Pertaining to or associated with men, or male animals; masculine. [from 16th c.]
- (figuratively) Of instruments, tools, or connectors: designed to fit into or penetrate a "female" counterpart, as in a connector or pipe fitting. [from 16th c.]
- Belonging to the masculine (social) gender.
- (grammar, less common than 'masculine') Masculine; of the masculine grammatical gender.
- Belonging to the sex which typically has testes, which in humans and most other mammals is typically the one which has XY chromosomes. [from 14th c.]
- (biology) Inherently characteristic of the male of a species. [from 17th c.]
- An animal of the sex that has testes.
- A human member of the masculine sex or gender.
- One of the male (masculine) sex or gender.
- A plant of the masculine sex.