flinch vs recoil

flinch and recoil both are nouns.

Word	Noun	Adjective	Verb	Adverb
flinch	Yes	No	Yes	No
recoil	Yes	No	Yes	No

As verbs, flinch and recoil are synonyms defined as:

Other synonyms of flinch include cringe, funk, quail, shrink, squinch, wince.

flinch (noun)	recoil (noun)
a reflex response to sudden pain	a movement back from an impact
	the backward jerk of a gun when it is fired

flinch (verb)	recoil (verb)
draw back, as with fear or pain	spring back, as from a forceful thrust
	draw back, as with fear or pain
	spring back; spring away from an impact
	come back to the originator of an action with an undesired effect