Meaning of open one's big mouth | Babel Free

Verb CEFR C2

Definitions

To speak about things rashly or foolishly, when it would be better to stay silent.

informal

Français ouvrir sa grande gueule

Polski gadać jak najęty gadać, co ślina na język przyniesie kłapać dziobem

Русский распустить язы́к язы́к зачесался

“Grr, why do I always open my big mouth after doing something wrong?”

Mastery
This word is part of the CEFR C2 vocabulary — mastery level.