Meaning of “flinch” - Learner’s Dictionary

flinch

verb [ I ] uk us /flɪntʃ/
MOVE BACKWARDS

to make a sudden movement backwards because you are afraid or in pain:

She didn't flinch when the nurse cleaned the wound.
AVOID DOING

to avoid doing something that is unpleasant:

Nick never flinches from difficult decisions.

(Definition of “flinch” from the Cambridge Learner’s Dictionary © Cambridge University Press)