'unparalleledness' originates from English, specifically formed from the adjective 'unparalleled' plus the suffix '-ness' (a noun-forming suffix meaning 'state or quality').

'unparalleled' is built from the prefix 'un-' (Old English, meaning 'not') and 'parallel' (from Middle English via Old French and Latin). 'Parallel' ultimately comes from Greek 'parallēlos' (para 'beside' + allēlos 'one another'); the modern noun 'unparalleledness' was formed by adding '-ness' to the adjective 'unparalleled'.

Originally, 'parallel' meant 'lying side by side'; 'unparalleled' meant 'not parallel' or 'without a parallel', and over time the derived noun 'unparalleledness' came to be used to denote the quality of having no equal or match.