volte-face
noun
[ vɒltˈfas ]
• an act of turning round so as to face in the opposite direction.
• an abrupt and complete reversal of attitude, opinion, or position.
• "a remarkable volte-face on taxes"
Origin:
early 19th century: from French, from Italian voltafaccia, based on Latin volvere ‘to roll’ + facies ‘appearance, face’.