let loose

verb3

1. •
   To free; to release from restraint.

   • I can imagine the man . . . prepared to oppress rival firms, overthrow inconvenient monarchs, and let loose the dogs of war. — 1892
2. •
   To shout, make a loud sound, or perform a sudden, vehement action; to behave in a raucous, frenzied manner.

   • He set his teeth, and let loose with a fury before which nothing could stand; and Maurice was forced back step by step until he was almost up with the wall. — 1901
3. •
   (euphemistic) To break wind.

   • Sorry for letting loose.