big mouthnoun [ C usually singular ]
uk/ˈbɪɡ ˌmaʊθ/us/ˈbɪɡ ˌmaʊθ/informal disapprovingIf someone is or has a big mouth, they often say things that are meant to be kept secret:
He is/has such a big mouth.
He went and opened his big mouth and told them the whole story.
I'm sorry. I wasn't supposed to tell you! Me and my big mouth!
Thesaurus: synonyms and related words
People who reveal secrets & tell tales
- blabbermouth
- dobber
- fink
- grass
- informer
- nark
- rat
- rumour-monger
- scandalmonger
- scaremonger
- sneak
- snitch
- source
- stool pigeon
- supergrass
- tattletale
- telltale
- whistle-blower