unnerve
VerbWordNet 3.0
Webster's Dictionary (GCIDE)
Unnerve \Un*nerve"\, v. t. [1st pref. un- + nerve.] To deprive of nerve, force, or strength; to weaken; to enfeeble; as, to unnerve the arm. [1913 Webster]
Unequal match'd, . . . The unnerved father falls. --Shak. [1913 Webster]