'anti-socialistic' originates from a combination of elements: the prefix 'anti-' (from Greek 'anti', meaning 'against') and 'socialistic' (from 'socialistic', ultimately from French 'socialisme' and Latin 'socius' meaning 'companion').

'anti-' + 'socialistic' formed in modern English by compounding the productive opposing prefix 'anti-' with the adjective 'socialistic' (itself derived from 'socialism' from French 'socialisme', and 'social' from Latin 'socius'), producing 'anti-socialistic' to mean 'against socialism'.

Initially it literally meant 'against socialism' (with 'anti-' = 'against' and 'socialistic' = 'of or relating to socialism'); over time the compound has retained that core sense and continues to mean opposition to socialist ideas or policies.