bigmouthed

/ˈbɪɡˌmaʊðd/
adjective
  1. Tending to talk too much or in a boastful, indiscreet way.
    • She's too bigmouthed to keep a secret.
    • The bigmouthed fan kept shouting during the entire movie.
    • His bigmouthed comments got him into trouble at work.
Antonyms
What does "bigmouthed" mean? | whatsthatwordmean | whatsthatwordmean