'non-mythic' originates from Latin and Ancient Greek: specifically the prefix 'non' from Latin 'non', where 'non' meant 'not', and 'mythic' from Greek 'mythos', where 'mythos' meant 'story' or 'tale'.

'non-mythic' developed by combining the negating prefix 'non-' with the adjective 'mythic' (from Greek 'mythos' via Latin and Middle English) and has been used in Modern English in the same combined form 'non-mythic'.

Initially it simply meant 'not part of a myth' or 'not belonging to traditional tales'; over time it has been used more broadly to contrast phenomena that are factual, ordinary, or nonlegendary with those that are mythic or legendary.