Nouns

(n)about-face, about turnact of pivoting 180 degrees, especially in a military formation
(n)about-face, volte-face, reversal, policy changea major change in attitude or principle or point of view“an about-face on foreign policy”

Verbs

(v)about-faceturn, usually 180 degrees
(v)about-facechange one's mind and assume the opposite viewpoint