to act prematurely
Examples:
- Don’t jump the gun and go home early without getting permission from the boss.
- If you jump the gun, you will be disqualified from the race.
- I don't want to jump the gun, but is this not what we discussed in yesterday's meeting?
- The press release jumped the gun by announcing the deal before it was signed.
Origin: From athletics, where a false start occurred if a competitor began running before the starting gun fired.
Synonyms: act prematurely, get ahead of oneself, rush ahead