means to flinch or recoil slightly, often with a tightening of the face, in reaction to pain, embarrassment, or anticipated unpleasantness

from From Middle English wincen, "to kick or shy away," likely borrowed from Old North French wencir/wenchier, "to wince or recoil" — a cousin of words meaning "to turn aside." It began life describing a horse's skittish startle or kick, then narrowed over centuries into the small human shrink we know now: the body's involuntary turning-away from something it would rather not meet.