bigmouth

[ big-mouth ]
/ ˈbɪgˌmaʊθ /

noun, plural big·mouths [big-mouth z, -mouths] /ˈbɪgˌmaʊðz, -ˌmaʊθs/ for 1; (especially collectively) big·mouth, (especially referring to two or more kinds or species) big·mouths for 2.

a loud, talkative person, especially one who lacks discretion.
any of several fishes having an unusually large mouth.

Origin of bigmouth

An Americanism dating back to 1885–90; big1 + mouth

British Dictionary definitions for big mouth

bigmouth
/ (ˈbɪɡˌmaʊθ) /

noun

slang a noisy, indiscreet, or boastful person

Derived forms of bigmouth

big-mouthed, adjective