u-turn vs turnaround

u-turn and turnaround both are nouns.

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

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

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

u-turn (noun)	turnaround (noun)
complete reversal of direction of travel	turning in the opposite direction
	act or process of unloading and loading and servicing a vessel or aircraft for a return trip
	an area sufficiently large for a vehicle to turn around
	a decision to reverse an earlier decision
	time need to prepare a vessel or ship for a return trip