'denominative' originates from Latin, specifically the Medieval/Neo-Latin word 'denominativus', where the element 'de-' functioned as an intensifier or 'from' and 'nomin-' (from 'nomen' / 'nominare') meant 'name' or 'to name'.

'denominativus' in Medieval/Neo-Latin passed into English via scholarly/technical Latin usage; the English adjective 'denominative' was formed by direct adoption and adaptation of this Latin-derived formation.

Initially it meant 'pertaining to naming or to a name', and over time this core sense has largely remained, with specialized use in linguistics to mean 'derived from a noun'.