defend vs turn back

defend and turn back both are verbs.

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

As verbs, turn back is a hyponym of defend; that is, turn back is a word with a more specific, narrower meaning than defend:

defend: be on the defensive; act against an attack
turn back: hold back, as of a danger or an enemy; check the expansion or influence of

Other hyponyms of defend include bulwark, protect, ward off, arrest, check, contain, hold back, stop.

defend (verb)	turn back (verb)
argue or speak in defense of	go back to a previous state
state or assert	turn inside out or upside down
be on the defensive; act against an attack	hold back, as of a danger or an enemy; check the expansion or influence of
protect against a challenge or attack	retrace one's course
protect or fight for as a champion	force to go away; used both with concrete and metaphoric meanings
fight against or resist strongly
be the defense counsel for someone in a trial