'mythify' originates from Modern English, specifically the combination of 'myth' and the verb‑forming suffix '-ify', where 'myth' ultimately comes from Greek 'muthos' meaning 'story' or 'speech' and '-ify' is a productive suffix (via Latin/French) meaning 'to make'.

'myth' passed from Greek 'muthos' into Latin ('mythus') and through medieval and Middle English (e.g. Middle English 'mythe') as 'myth'; the suffix '-ify' derives from Latin 'facere' through Old French/Latin suffixes (‑ificare/‑ifier), and combining them in Modern English produced 'mythify'.

Initially related to 'muthos' meaning 'story' or 'speech', the formation 'mythify' developed in Modern English to mean 'to make something into a myth' or 'to idealize/romanticize' in contemporary usage.