'antimysticism' originates from the combining of the prefix 'anti-' (from Greek 'anti' meaning 'against') and the noun 'mysticism' (from Greek 'mustikos' via Latin and French).

'mysticism' changed from Greek 'mustikos' -> Late Latin 'mysticus' -> Old French 'mysticisme' -> Middle English 'mysticism', and the prefix 'anti-' (Greek 'anti') was attached in modern English to form 'antimysticism'.

Initially, the components meant 'against' + 'pertaining to the mysteries' (i.e., opposition to mystical practices or doctrines); over time the compound has been used to denote a general critical stance toward mysticism in philosophy, theology, and culture.