'single-nerved' originates from Modern English, formed by the compound of 'single' and 'nerved' (the adjectival/past-participle form of 'nerve'). 'Single' ultimately comes from Latin 'singulus' (via Old French/Middle English), and 'nerve' comes from Latin 'nervus' (via Old French and Middle English).

'single-nerved' developed as a compound adjective in late Middle/Modern English by combining 'single' + past-participle/adjectival use of 'nerve' ('nerved'). The component words evolved from Latin 'singulus' and 'nervus' through Old French and Middle English into their current forms.

Initially it meant 'possessing a single nerve or vein' (used especially in botanical and anatomical description); this specific, literal meaning has largely been retained, though the term is relatively rare in modern general usage.