'anticommunist' originates from modern English, formed by the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'communist' (from French 'communisme' ultimately from Latin 'communis' meaning 'common').

'communist' developed from French 'communisme' (from Latin 'communis' 'common'); 'anticommunist' was formed in English in the late 19th to early 20th century as political movements and debates about communism grew, combining 'anti-' + 'communist'.

Initially it meant 'against or opposed to communism' in a political sense, and that core meaning has largely remained the same into modern usage.