'pro-mysticism' originates from a combination of the Latin prefix 'pro-' (from Latin 'pro', meaning 'for' or 'forward') and the noun 'mysticism', which itself derives from Greek 'mystikos' (via Late Latin 'mysticus' and Middle English) referring to mysteries or mystical rites.

'pro-mysticism' is a modern English compound formed by attaching the prefix 'pro-' to the established English noun 'mysticism'; 'mysticism' changed from Greek 'mystikos'/'mystēs' to Late Latin 'mysticus' and then into Middle and Modern English as 'mysticism'.

Initially the elements conveyed 'for' (pro-) and 'secret/initiatory rites or mystical knowledge' (mystikos), but the compound's contemporary meaning is simply 'support for or advocacy of mysticism'.