'antianarchist' originates from Modern English, specifically formed from the prefix 'anti-' (from Greek 'antí', meaning 'against') combined with the word 'anarchist' (from French 'anarchiste', ultimately from Greek 'anarkhēs').

'antianarchist' developed as a direct compound in English from 'anti-' + 'anarchist'. 'Anarchist' itself came into English via French 'anarchiste', which traces back to Greek 'anarkhēs' ('an-' meaning 'without' and 'arkhēs' meaning 'ruler'), and the prefix 'anti-' came into English from Greek through Latin and French.

Initially the elements meant 'against' (anti-) and 'without ruler' (an- + arkhos), and over time 'anarchist' came to mean 'one who supports abolition of government'; 'antianarchist' therefore has come to mean 'opposed to anarchists or anarchism' and has retained that specific opposing sense.