go back vs turn back

go back and turn back both are verbs.

Word	Noun	Adjective	Verb	Adverb
go back	No	No	Yes	No
turn back	No	No	Yes	No

As verbs, turn back is a hypernym of go back; that is, turn back is a word with a broader meaning than go back:

Other hypernyms of go back include regress, retrovert, return, revert.

go back (verb)	turn back (verb)
regain a former condition after a financial loss	go back to a previous state
return in thought or speech to something	turn inside out or upside down
belong to an earlier time	hold back, as of a danger or an enemy; check the expansion or influence of
	retrace one's course
	force to go away; used both with concrete and metaphoric meanings