u-turn vs reversal

u-turn and reversal both are nouns.

Word	Noun	Adjective	Verb	Adverb
u-turn	Yes	No	No	No
reversal	Yes	No	No	No

As nouns, reversal is a hypernym of u-turn; that is, reversal is a word with a broader meaning than u-turn:

Other hypernyms of u-turn include reverse, reversion, turnabout, turnaround.

u-turn (noun)	reversal (noun)
complete reversal of direction of travel	a change from one state to the opposite state
	the act of reversing the order or place of
	turning in the opposite direction
	a major change in attitude or principle or point of view
	a judgment by a higher court that the judgment of a lower court was incorrect and should be set aside
	a decision to reverse an earlier decision
	turning in an opposite direction or position
	an unfortunate happening that hinders or impedes; something that is thwarting or frustrating