'nonheroic' originates from Latin and Greek elements: the prefix 'non' (Latin 'non') and the adjective-forming element from Greek 'hērōikos' (from 'hērōs'), where 'non' meant 'not' and 'hērōs' meant 'hero'.

'nonheroic' developed in Modern English by combining the negative prefix 'non-' with the adjective 'heroic'. 'Heroic' entered English via Middle English and Old French (from Latin 'heroicus', from Greek 'hērōikos'), while the prefix 'non-' comes via Latin use as a negator; together they produced the straightforward compound 'nonheroic'.

Initially it simply meant 'not heroic' (the straightforward negation of 'heroic'); over time the term has been used both descriptively (lacking heroism) and stylistically (deliberately unglamorous or modest), but its core sense remains 'not heroic'.