an underwater mine set off by any disturbance of its magnetic field, as by the metal hull of a ship.
Origin of magnetic mine
First recorded in 1935–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a mine designed to activate when a magnetic field such as that generated by the metal of a ship's hull is detected
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012