spout off

/S P AW1 T AO0 F/
verb
  1. 1

    (informal) To speak for a tedious or exasperating length of time.

  2. 2

    (informal) To speak in a particularly boastful or arrogant manner.

  3. 3

    (informal) To utter something in a brash, unwelcome, or unpleasant manner.