'antirevolutionary' originates from a combination of the prefix 'anti-' (from Greek 'anti' meaning 'against') and 'revolutionary' (from 'revolution'), the latter ultimately from Latin 'revolutio' meaning 'a turn around'.

'antirevolutionary' was formed in English by combining 'anti-' + 'revolutionary', influenced by similar formations in French (e.g. 'antirévolutionnaire'); 'revolution' itself comes from Latin 'revolutio' and passed into English via Old French and Middle English.

Initially it plainly meant 'against revolution' in a political sense; over time it has retained that core political meaning and is still used to describe opposition to revolutionary movements or ideas.