'homonymous' originates from Greek, specifically the word 'homōnumos', where 'homō-' meant 'same' and 'onoma' meant 'name'.

'homonymous' changed from Greek 'homōnumos' into Latin/Medieval Latin 'homonymus' and then entered English via Late Latin/Old French influences, eventually becoming the modern English word 'homonymous'.

Initially, it meant 'having the same name', and over time it has retained this core meaning while being applied in linguistics and taxonomy to describe words or names that share form but differ in meaning or reference.