1.n. a person who talks too much or too loudly; someone who tells secrets. (Also a term of address.) Okay, big mouth! Shut up! 2.tv. to spread secrets around. Why do you always have to big mouth everything around?
A very talkative or boastful person; also, loquacity, boastful talk. (1889 —) . E.Coxhead He was a big mouth. He picked up strangers...and told them the story of his life (1951). Hence big-mouthed, adjective Loquacious or boastful. (1914 —) .