'underwater mine' definitions:

Definition of 'underwater mine'

From: GCIDE

marine mine \ma*rine" mine`\, n. (Mil.) A military explosive device designed to be placed on or under the surface of a body of water, and to explode when ships pass nearby or come in contact with it. Its function is to destroy enemy ships or deny hostile naval forces access to certain areas of the sea, usually near the shoreline. Also called underwater mine and floating mine, and previously referred to as a torpedo (See torpedo[2] (a) ). [PJC]