bench jockey

Meanings:

• 1.

  American EnglishBritish Englishgeneralinformalslang
  • A person who heckles, taunts, or jeers from the sidelines at sporting events, especially in boxing, wrestling, or team sports.
  • A person who offers loud, often abusive or mocking commentary directed at players, opponents, or officials while remaining on the sidelines.

• 2.

  generalinformalslang
  • A person who repeatedly offers sarcastic, derisive, or provocative comments from a position of nonparticipation or safety; a loud or persistent heckler in any public context.