mouth off

British

verb

informal to give an opinion or speak emotionally, often without much care or consideration

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

mouth off Idioms

Complain or express one's opinions loudly and indiscreetly, as in She was always mouthing off about the other members . [ Slang ; 1960s]
Speak impudently, talk back, as in He got in trouble by mouthing off to his teacher . [ Slang ; 1960s]

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

mouth off

Yet apparently it’s just easier for people to mouth off without doing any research at all.

From MarketWatch ● Jun. 5, 2026

Horseradish isn’t clamoring to burn your mouth off.

From Salon ● Sep. 2, 2025

Westminster is full of people who love shouting their mouth off.

From BBC ● Jul. 5, 2022

"She's trying to defend her daughter, why doesn't she stop shouting her mouth off and take ownership of how she raised her daughter," Imbriale told Fox News Digital Tuesday.

From Fox News ● Jan. 11, 2022

He glared at Percy, daring him to mouth off.

From "The Mark of Athena" by Rick Riordan

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023