'antimonarchy' originates from Greek and Modern English, formed by the prefix 'anti-' (from Greek 'anti') meaning 'against' combined with 'monarchy' ultimately from Greek 'monarkhia', where 'monos' meant 'one' and 'arkhein' meant 'to rule'.

'antimonarchy' was created in Modern English by prefixing 'anti-' to the existing word 'monarchy'; 'monarchy' itself passed into English via Latin 'monarchia' and Old French 'monarchie' from Greek 'monarkhia'.

The root 'monarchy' originally meant 'rule by one'; 'antimonarchy' has meant 'opposition to rule by a monarch' since its formation and retains that political sense.