to set off, trigger

(しょくはつ) To trigger a controversy, war, or to catalyze a chemical reaction. Not necessarily intentional.
しげき To intentionally provoke someone or something. Not always bad  – you can stimulate a baby by tickling it, or stimulate a patient with electrodes.
しょうらい A very literary word which you don’t have to worry about.
(ひきがね) Is literally a trigger, but I’ve seen it used as a metaphor too.