reversal vs about-face

reversal and about-face both are nouns.

Word	Noun	Adjective	Verb	Adverb
reversal	Yes	No	No	No
about-face	Yes	No	Yes	No

As nouns, about-face is a hyponym of reversal; that is, about-face is a word with a more specific, narrower meaning than reversal:

Other hyponyms of reversal include about turn, u-turn.

As nouns, reversal and about-face are synonyms defined as:

reversal and about-face: a major change in attitude or principle or point of view

Other synonyms of reversal include policy change, volte-face.

reversal (noun)	about-face (noun)
a change from one state to the opposite state	a major change in attitude or principle or point of view
the act of reversing the order or place of	act of pivoting 180 degrees, especially in a military formation
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

reversal (verb)	about-face (verb)
	change one's mind and assume the opposite viewpoint
	turn, usually 180 degrees