1
general::
An area of tough competition and high rewards; the largest or foremost of its kind. For example, Winning an Oscar put this unknown actress in the big league. The term alludes to the major (big) leagues of American baseball. [Late 1800s] Also see BIG TIME, def. 2. big mouth, have a Also, have or be a loud mouth. Be loquacious, often noisily or boastfully; be tactless or reveal secrets. For example, After a few drinks, Dick turns into a loud mouth about his accomplishments, or Don't tell Peggy anything confidential; she's known for having a big mouth. [Slang; late 1800s]
American Heritage Idioms