What is About-face?

About-face definition and meaning on Dictionary terms:
Military. a turn of 180A? from the position of attention.
a complete, sudden change in position, direction, principle, attitude, etc.: They’ve done an about-face in their foreign policy.

verb (used without object), aA.bout-faced, aA.bout-facA.ing.
to execute an about face.
to turn in the opposite direction.
to switch to an opposite opinion.


reference: https://www.dictionary.com/browse/about-face