'anti-moral' originates from Modern English, formed from the prefix 'anti-' (from Greek 'anti' meaning 'against') and the adjective 'moral' (from Latin 'moralis' via Old French 'moral').

'moral' comes from Latin 'moralis' through Old French 'moral' and Middle English 'moral'; the productive prefix 'anti-' (Greek) combined with 'moral' in Modern English to create compounds such as 'anti-moral'.

Initially, 'moral' concerned customs, manners, and character; compounds like 'anti-moral' developed to denote opposition to prevailing moral standards, a meaning that has remained broadly consistent as 'against moral principles'.