'antiparliamentarian' originates from Modern English, formed from the prefix 'anti-' (from Greek 'anti' meaning 'against') and 'parliamentarian' (from 'parliament' with the suffix '-arian').

'parliament' came into English from Old French 'parlement' (from 'parler', 'to speak'); 'parliamentarian' developed in English to mean a supporter or member of a parliament, and the prefix 'anti-' was later attached to create 'antiparliamentarian'.

Initially, it meant 'against parliamentary institutions or principles', and over time this core meaning has remained largely unchanged, denoting opposition to parliamentary rule or supporters thereof.