[truhn-yuh n]


either of the two cylindrical projections on a cannon, one on each side for supporting the cannon on its carriage.
any of various similar supports for machinery.

Origin of trunnion

First recorded in 1615–25, trunnion is from the French word trognon trunk, stump, core (of fruit)
Related formstrun·nioned, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for trunnion

Historical Examples of trunnion

British Dictionary definitions for trunnion



one of a pair of coaxial projections attached to opposite sides of a container, cannon, etc, to provide a support about which it can turn in a vertical
the structure supporting such a projection
Derived Formstrunnioned, adjective

Word Origin for trunnion

C17: from Old French trognon trunk
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

Word Origin and History for trunnion

"either of two round projections of a cannon," 1620s, from French trognon "core of fruit, stump, tree trunk," from Middle French troignon (14c.), probably, from Latin truncus (see trunk).

Online Etymology Dictionary, © 2010 Douglas Harper