'anticivil' is formed in Modern English from the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'civil' (from Latin 'civilis' meaning 'relating to citizens or public life').

'civil' comes from Latin 'civilis' → Old French 'civil' → Middle English 'civil'; 'anti-' is from Greek 'anti-' and has been used in English since the Classical/Modern period to form opposites; 'anticivil' is a Modern English formation combining these elements.

Initially formed to convey being 'against civility' or 'not civil'; its current meaning remains essentially 'not civil; rude or uncivil'.