a device for shooting a barbed missile under water, usually by means of gas under pressure, a strong rubber band, or a powerful spring.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for spear gun
Historical Examples of spear gun
His spear-gun, the knife at his waist belt, neither were protection against this!
Ashe dug the butt of his spear-gun into the sand on the flooring to uncover another oval depression.
a device for shooting spears underwater
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