'antimorality' originates from Modern English, formed by the Greek-derived prefix 'anti-' (from Greek 'antí') meaning 'against' and the noun 'morality' (from Old French 'moralité', from Latin 'moralis'), where the root 'moralis' meant 'pertaining to manners or morals'.

'antimorality' developed as a compound in modern English by attaching 'anti-' to 'morality' (it follows formations like 'antidemocracy' or 'antinomian'), drawing on the older elements 'moral' (from Old French 'moral') and Latin 'moralis'; the idea of opposing 'moral' concepts can be traced through philosophical writings but the compound itself is a relatively recent English formation.

Initially, the elements meant 'against' + 'pertaining to morals'; over time the compound came to denote either a philosophical opposition to conventional morals or the quality of being hostile to moral norms, with some usage overlapping with 'immorality' but generally emphasizing opposition.