Flinch (verb)

1. To make a sudden, involuntary movement back or away from something, especially in fear or discomfort.
2. To show reluctance or hesitation to do something.

Origin:

The origin of the word 'flinch' is uncertain. it is believed to have come from a middle english word 'flenchen' which means to shrink away or draw back.

Examples:

1. She flinched when the door suddenly banged shut.
2. He flinched at the thought of having to face the media.
3. The dog flinched and growled as the vet approached.
4. She didn't flinch when she was told about her poor exam results.
5. He refused to flinch from his decision even in the face of criticism.