'anti-parliamentarian' originates from the prefix 'anti-' (from Greek anti- 'against') combined with 'parliamentarian' (from 'parliament'), where 'parliament' ultimately comes from Old French 'parlement' based on parler 'to speak'.

'parliament' came into Middle English from Old French 'parlement' (from parler 'to speak'), 'parliamentarian' developed in modern English to denote a supporter or member of a parliament, and the prefix 'anti-' was later attached to form 'anti-parliamentarian' meaning someone opposed to parliamentarianism; the plural form 'anti-parliamentarians' is the regular English plural.

Initially formed to denote opposition to the institution or principles of parliament, its core meaning has remained the same: people opposed to parliamentary government or parliamentary procedures.