'phallic' originates from Late Latin, specifically the word 'phallicus', where Greek 'phallos' meant 'penis'.

'phallic' changed from Late Latin 'phallicus' (from Greek 'phallos') into New Latin/Modern use and entered English as 'phallic' through scholarly and literary use.

Initially it meant 'relating to the phallus', and over time it has retained that core meaning while also coming to describe objects or imagery that symbolically suggest male sexuality or masculine power.