Meaning
To talk loudly, recklessly, or indiscreetly, especially about matters you do not fully understand or secrets you should keep. It almost always carries criticism, presenting the speaker's words as careless, excessive, and impossible to take back. Informal and disapproving; used about boastful, rash, or leaky talkers. Regional use: General English; originally American slang.
Origin
The OED documents to shoot off one's mouth from 1864 as slang that was originally American, defined as talking indiscreetly or abusively; Collins likewise labels the idiom 19th century and originally American. A 20th-century starting point, sometimes given, is too late. The imagery compares unrestrained speech to firing a gun without taking aim: words leave the mouth as bullets leave a barrel, fast, loud, and with little control over where they land. The related verb to mouth off, and the variant shooting off at the mouth, extend the same picture. No earlier literal sense is involved; the metaphor appears to be ballistic from the start, though that characterization of the image is inference from the wording.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- mouth off
- shoot off at the mouth
- shoot off one's mouth
- shoot one's mouth off
Usage Examples
- He shot his mouth off at the meeting and promised deadlines the team could never meet.
- Stop shooting your mouth off about the merger; the paperwork is still confidential.
- She regretted shooting her mouth off to the journalists before the votes were counted.