mouth off
In real, traceable use. Part of the curated seed collection; community review is coming.
Sense 1
Meaning · English
To complain or otherwise express oneself in a loud, immoderate manner.
Register: slang
Where it’s used:
Used
American English
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Sense 2
Meaning · English
To talk impudently, especially to one's superior.
Register: slang
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-07-30 via kaikki.org).
Common questions
What does “mouth off” mean?
To complain or otherwise express oneself in a loud, immoderate manner.
Is “mouth off” formal or informal?
mouth off is generally slang.