To Quail

1. (intransitive) To waste away; to fade, to wither [from 15th c.]
2. (transitive, now rare) To daunt or frighten (someone) [from 16th c.]
3. (intransitive) To lose heart or courage; to be daunted or fearful. [from 16th c.]
4. (intransitive) Of courage, faith, etc.: to slacken, to give way. [from 16th c.]