'unheroic' originates from English, specifically the prefix 'un-' + 'heroic', where 'un-' meant 'not' and 'heroic' ultimately derives from Greek 'hērōs' ('hero').

'heroic' changed from Old French 'heroique' (modern French 'héroïque') from Latin 'heroicus' from Greek 'hērōs'; the English negative prefix 'un-' was later added in Modern English to form 'unheroic'.

Initially, 'heroic' meant 'relating to or characteristic of a hero', so 'unheroic' originally meant simply 'not heroic'; over time 'unheroic' also acquired nuances such as 'cowardly', 'undignified', or 'unimpressive' in some contexts.