'antichristianism' originates from Greek and Late Latin elements: specifically the prefix 'anti-' from Greek 'anti' meaning 'against', plus 'Christian' from Late Latin 'Christianus' (from Greek 'Christianos') meaning 'a follower of Christ', and the suffix '-ism' from Greek/Latin '-ismos' indicating 'practice, system, or ideology'.

'antichristianism' developed in English by combining the adjective 'antichristian' (formed from 'anti-' + 'Christian') with the noun-forming suffix '-ism', producing a term referring to the ideology or stance opposed to Christianity.

Initially, formations like 'antichristian' or related terms primarily described opposition to Christian doctrine; over time 'antichristianism' has been used both for doctrinal opposition and for broader social or political hostility toward Christian institutions and believers.