Etymology: French, < Italian volta faccia, < volta turn + faccia face.
The act of turning so as to face in the opposite direction; fig. a complete change of attitude or opinion. (OED)
"This was quite a volte-face for Morgan, but it was just the start. The eye-color ratios convinced him that gene theory wasn't bunk."
- Sam Kean, The Violinist's Thumb and Other Lost Tales of Love, War, and Genius, as Written by our Genetic Code