UNNERVE

faze, unnerve, enervate, unsettle

(verb) disturb the composure of

Source: WordNet® 3.1

Etymology

Verb

unnerve (third-person singular simple present unnerves, present participle unnerving, simple past and past participle unnerved)

To deprive of nerve, force, or strength; to weaken; to enfeeble.

To make somebody nervous, upset, alarm, shake the resolve of.

Source: Wiktionary

Un*nerve", v. t. Etym: [1st pref. un- + nerve.]

Definition: To deprive of nerve, force, or strength; to weaken; to enfeeble; as, to unnerve the arm. Unequal match'd, . . . The unnerved father falls. Shak.

Source: Webster’s Unabridged Dictionary 1913 Edition