[trig.ger] n [alter. of earlier tricker, fr. D trekker, fr. MD trecker one that pulls, fr. trecken to pull--more at trek] (1621) 1 a: a piece (as a lever) connected with a catch or detent as a means of releasing it; esp: the part of the action moved by the finger to fire a gun b: a similar movable part by which a mechanism is actuated "~ of a spray gun"
2: something that acts like a mechanical trigger in initiating a process or reaction -- trigger adj -- trig.gered adj
[2]trigger vb trig.gered ; trig.ger.ing vt (1916) 1 a: to release or activate by means of a trigger; esp: to fire by pulling a mechanical trigger "~ a rifle" b: to cause the explosion of "~ a missile with a proximity fuze"
2: to initiate, actuate, or set off by a trigger "an indiscreet remark that ~ed a fight" "a stimulus that ~ed a reflex" ~ vi: to release a mechanical trigger