a movable piece of metal for closing the breech in certain firearms.
Origin of breechblock
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for breechblock
Historical Examples of breechblock
Breechblock—a movable piece which closes the breech of a cannon.Artillery Through the Ages
a metal block in breech-loading firearms that is withdrawn to insert the cartridge and replaced to close the breech before firing
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