Definition of triggers:
(n) :
(firearms) A finger-operated lever used to fire a gun.
(n) :
An event that initiates others, or incites a response.
(n) :
A similar device used to activate any mechanism.
(v) :
(transitive) To cause, to precipitate, to bring (something) about in response or as a result.
(v) :
(transitive, figurative) To spark a response, especially a negative emotional response, in (a person).
(n) :
(psychology) An event, experience or other stimulus that initiates a traumatic memory or a strong reaction in a person.