'anti-Constitution' originates from Modern English, combining the prefix 'anti-' (from Greek 'anti' meaning 'against') with 'Constitution' (from Latin 'constitutio').

'Constitution' derives from Latin 'constitutio' (from 'constituere'), passed through Old French and Middle English (e.g. Middle English 'constitucioun') and became modern English 'Constitution'; the productive prefix 'anti-' was borrowed from Greek into English in modern formation of compounds.

Initially, Latin 'constitutio' related to 'the act of setting up' or an established arrangement; over time it came to mean 'a system of fundamental laws' in modern usage. With the prefix 'anti-', the compound's meaning developed into 'against that system or law' (i.e., 'against the constitution').