trunnion noun. ['trʌnjǝn] E17.
[Old & mod. French trognon core of fruit, trunk of a tree, of unkn. origin.]
1. Either of a pair of cylindrical projections on opposite sides of a cannon or mortar, by which it is pivoted on its carriage. E17.

2. Either of any similar pair of opposing pins or pivots, on which a thing is supported; spec. in an oscillating steam engine, a hollow gudgeon on each side of the cylinder, on which it pivots and through which steam passes in and out. Also, a single projecting peg or pivot. E18.

[TahlilGaran] English Dictionary ▲