let fly vs sling

let fly

verb
  • To strike or release a projectile with great force. 

  • To unleash an angry outburst. 

  • She was furious and let fly at him with a string of obscenities. 

sling

verb
  • To pass a rope around (a cask, gun, etc.) preparatory to attaching a hoisting or lowering tackle. 

  • To throw with a sling. 

  • To throw with a circular or arcing motion. 

  • To sell, peddle, or distribute (often illicitly, e.g. drugs, sex, etc.). 

noun
  • A strap attached to a firearm, for suspending it from the shoulder. 

  • A loop of rope or fabric tape used for various purposes: e.g. as part of a runner, or providing extra protection when abseiling or belaying. 

  • A drink composed of a spirit (usually gin) and water sweetened. 

  • A loop of cloth, worn around the neck, for supporting a baby or other such load. 

  • A band of rope or iron for securing a yard to a mast. 

  • The act or motion of hurling as with a sling; a throw; figuratively, a stroke. 

  • A loop of rope, or a rope or chain with hooks, for suspending a barrel, bale, or other heavy object, in hoisting or lowering. 

  • An instrument for throwing stones or other missiles, consisting of a short strap with two strings fastened to its ends, or with a string fastened to one end and a light stick to the other. 

  • A kind of hanging bandage put around the neck, in which a wounded arm or hand is supported. 

  • A young or infant spider, such as one raised in captivity. 

How often have the words let fly and sling occurred in a corpus of books? (source: Google Ngram Viewer )