'archmocker' originates from English, formed by the combining prefix 'arch-' (from Greek 'arkhos', meaning 'chief' or 'principal') and the noun 'mocker' (one who mocks).

'arch-' entered English via Latin/Old French influence and became a productive intensifying prefix in Middle to Early Modern English; 'mocker' developed from the verb 'mock' (Middle English forms such as 'mokken' or 'mocken'), and 'archmocker' is a modern English compound formed by joining these elements.

Initially a literal compound meaning 'chief mocker' (the foremost one who mocks); over time it retains that emphatic sense of an extreme or habitual mocker.