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
2.
the structure supporting such a projection
Derived forms
trunnioned (ˈtrunnioned)
adjective
Word origin
C17: from Old French trognon trunk
trunnion in American English
(ˈtrʌnjən)
noun
1.
either of two projecting pivots, located on each side of a cannon or its mount, by which the muzzle is raised and lowered