trigger

definition: 
to initiate; cause or start
sentence: 
Many people who've had a heart attack worry that too much physical activity could trigger a repeat event.
Sometimes everyday items like dust or nuts can trigger your allergies, leave you with a skin infection, or cause other problems.
difficulty: 
very easy
toefl frequency: 
2
toefl classification: 
adverb: 
adjective: 
triggered
adverb sentence: 
adjective sentence: 
verb: 
trigger
verb sentence: 
noun: 
noun sentence: