The Collaborative International Dictionary of English v.0.48:
Unbrace \Un*brace"\, v. t. [1st pref. un- + brace.] To free from tension; to relax; to loose; as, to unbrace a drum; to unbrace the nerves. --Spenser. [1913 Webster]WordNet (r) 3.0 (2006):
unbrace v 1: undo the ties of; "They untied the prisoner" [syn: untie, unbrace, unlace] [ant: bind, tie] 2: remove from tension 3: remove a brace or braces from