spec. An elephant's tusk (projecting upper incisor tooth), as a source of ivory.

†The tusk of an elephant (obsolete); the tusk of a narwhal.

concrete. That which serves as a defence. spec. The tusk of an elephant (= French défense). Also, the involucre of a flower. Obsolete.

A small elephant's tusk, used esp. in the manufacture of billiard balls. Usually in plural.

Used in plural for the prongs of a fork. Also transferred. Cf. 12.