A recoil is a movement backwards, usually from some force or impact. The recoil of a gun is a backward movement caused by momentum. Your trip to the shooting range might make your mom recoil — from horror, not momentum.
Recoil has both a verb and a noun form, meaning any kind of rebound or spring backwards. It doesn’t even have to be from an actual force. You might recoil when you see a snake, or recoil at the thought of having to eat squid. In those cases it’s more like a cringe or a flinch from something that’s scary, disgusting, or painful. Eating squid might in fact be all of those things to you.