'anti-moralist' originates from modern English, specifically the combination of the prefix 'anti-' (from Greek 'anti-' meaning 'against') and 'moralist' (an agent noun from 'moral').

'moralist' comes into English via French 'moraliste' (17th c.), ultimately from Latin 'moralis' (from 'mos, mores' meaning 'customs'). The prefix 'anti-' is from Greek 'antí-' meaning 'against' and was productive in English from the 16th–17th centuries onward; these elements combined in modern English to form 'anti-moralist'.

Initially the parts meant 'against' + 'one concerned with morals'; over time the compound has been used to denote someone opposed to moralism or to moralizing attitudes, broadening from a literal opposition to moralists to a general stance against moralistic social pressures.