A marine tortoise or turtle. Also in combination sea-tortoiseshell.

transferred. Used as a name for various animals, fishes, etc. A turtle. Obsolete.

Any species of marine tortoise; also extended to various other tortoises. (Plural turtles, collectively usually turtle.)

A marine tortoise or turtle.

(a) jocular a sailor, esp. a hardened or experienced one; also transferred; (b) a marine turtle.

= turtle, n.2

Applied to the turtle.