'designatively' originates from English, specifically the adjective 'designative', ultimately from Latin 'designare', where 'de-' meant 'away/completely' and 'signare' meant 'to mark'.

'designatively' developed from the Modern English adjective 'designative' (formed from the verb 'designate' + adjectival suffix '-ive'); 'designate' came into English via Middle French 'designer' from Latin 'designare', and the adverb was formed by adding the suffix '-ly' to 'designative'.

Initially (from Latin 'designare') it meant 'to mark out or indicate'; over time this evolved into the adjective meaning 'serving to designate' and the adverb meaning 'in a manner that designates' as used in modern English.