the word 'unstrung' is a compound formed within english from the native prefix 'un-' and the past participle 'strung'. the core verb 'string' originates from old english 'streng', related to the concept of a cord or line, and by extension, to the act of fitting something with such a cord, as on a bow or musical instrument. the prefix 'un-' applied to the participle creates a sense of reversal, literally meaning 'not strung' or 'having had the stringing undone'. this literal sense evolved metaphorically to describe a person whose nerves or composure have come undone, as if the tension has been released from their emotional strings.

Structure: un (not) + strung (past participle of 'string') un- (old english, a prefix meaning 'not' or 'reverse of an action'); strung (old english, past participle of 'string', from the root meaning 'to bind or fit with a cord').