- 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)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for trunnion
Had not he possessed that, he would not have been at the head of the firm of Crank, Trunnion & Swab.
Mr Trunnion was silent for a minute, and seemed lost in thought.
All I know is, that Mr Trunnion did not invite him to his house.
“The time has come to set Captain Trunnion at liberty,” I said.
Sir Philip, however, was by no means one of the Trunnion class.Club Life of London, Vol. I (of 2)
- 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
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