|ən+ adjective
Etymology: partly from un- (I) + braced, past participle of brace; partly from past participle of obsolete English unbrace to unfasten, remove clothing or armor from, from Middle English unbracen
1.
a. obsolete : not tied by braces
his doublet all unbraced — Shakespeare
b. : wearing unfastened or loosened clothing
2.
a. obsolete , of a drum : not taut : free from tension
b. : unflexed , relaxed