'anti-egotist' originates from Modern English, specifically the combination of the prefix 'anti-' and the word 'egotist', where 'anti-' meant 'against' and 'egotist' meant 'a person exhibiting egotism (excessive self-interest or vanity)'.

'egotist' ultimately derives from Latin 'ego' meaning 'I' with the agentive suffix '-ist' (and was attested in French as 'égotiste'); the prefix 'anti-' comes from Greek 'anti-' meaning 'against' and entered English via Latin/Old French formation, producing the compound 'anti-egotist' in Modern English.

Initially, the components meant 'against' + 'a self-centered person', and the compound has retained that sense: someone opposed to egotism or self-centered behavior.