coming back vs turning

coming back and turning both are nouns.

Word	Noun	Adjective	Verb	Adverb
coming back	Yes	No	No	No
turning	Yes	No	No	No

As nouns, turning is a hypernym of coming back; that is, turning is a word with a broader meaning than coming back:

coming back: the occurrence of a change in direction back in the opposite direction
turning: a movement in a new direction

Other hypernyms of coming back include turn.

coming back (noun)	turning (noun)
the occurrence of a change in direction back in the opposite direction	the act of changing or reversing the direction of the course
	act of changing in practice or custom
	the activity of shaping something on a lathe
	the end-product created by shaping something on a lathe
	a movement in a new direction
	a shaving created when something is produced by turning it on a lathe