Definition of "trench mortar" []

• A mortar usually ranging from 3 to 9.45 inches in caliber, designed for use in forward positions, especially in trenches. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.