'anticommunistical' originates from Modern English, formed by the prefix 'anti-' (originally from Greek 'anti' meaning 'against') + 'communist' (from 'communism') and the adjectival suffix '-ical' (via Latin/French adjectival formation).

'anticommunistical' developed as an extended adjective from the compound 'anti-communist' (formed in Modern English). 'Communist' itself comes from French 'communiste' (19th century), ultimately from Latin 'communis' meaning 'shared, common'. Over time English formed adjectives like 'communistic' and 'communist' and then compounds with the prefix 'anti-'.

Initially the elements referred broadly to being 'against communal/shared (ideas)' or against movements for communal ownership; over time the compound came to mean specifically 'opposed to the political ideology of communism' and its supporters.