'anti-mythical' originates from Modern English, specifically the prefix 'anti-' (from Greek ἀντί 'antí') meaning 'against' and 'mythical', derived from 'myth' (Greek 'mythos') meaning 'story' or 'tale', with the adjectival suffix '-ical'.

'anti-mythical' was formed in Modern English by combining the productive prefix 'anti-' with the adjective 'mythical' (itself from 'myth' via Old French/Latin from Greek 'mythos'), following common compounding patterns.

Originally 'mythos' meant 'story' or 'tale'; 'mythical' meant 'relating to myths'. 'Anti-mythical' developed to mean 'against or rejecting myths' or 'tending to debunk mythic accounts'.