pull the trigger

Verb

pull the trigger (third-person singular simple present pulls the trigger, present participle pulling the trigger, simple past and past participle pulled the trigger)

1. To fire a gun.
2. (idiomatic) To commit to a course of action.
   • Most surprisingly of all, the mad queen Cersei is challenged to execute both of her brothers at different moments, and she can’t bear to pull the trigger either time.2017 August 27, Brandon Nowalk, “Game Of Thrones slows down for the longest, and best, episode of the season (newbies)”, in The Onion AV Club
   • Some traders are too afraid to pull the trigger and just watch the market without ever getting involved.2003, Marcel Link, High Probability Trading: Take the Steps to Become a Successful Trader, page 377
3. (idiomatic, intransitive) To shoot, kick the ball in hope of scoring a goal.
   • The Baggies almost hit back instantly when Graham Dorrans broke from midfield and pulled the trigger from 15 yards but Paul Robinson did superbly to tip the Scot's drive around the post.2010 December 28, Kevin Darlin, “West Brom 1 - 3 Blackburn”, in BBC
4. (informal) To hit a very powerful shot.