'amoralistic' originates from English, formed by combining the prefix 'a-' (from Greek, meaning 'not') with 'moral' (from Latin 'moralis', 'relating to manners') plus the adjectival suffix '-istic' (from Greek '-istikos', 'pertaining to').

'amoralistic' developed in modern English by adding the suffix '-istic' to 'amoral'. 'Amoral' itself comes from prefix 'a-' + 'moral', with 'moral' entering English via Old French 'moral' from Latin 'moralis', ultimately from Latin 'mos, moris' meaning 'custom' or 'habit'.

Initially the components conveyed simply 'not moral' (absence of moral quality); over time the combined form came to be used to describe attitudes, philosophies, or rhetorical tones that are indifferent to or reject conventional moral judgments.