'balneological' originates from Latin and Greek, specifically the Latin word 'balneum' and the Greek word 'balaneion', where 'balne-' meant 'bath'.

'balneological' changed from the noun 'balneology' (formed from Latin/Greek roots meaning 'bath') and the English adjective was produced by adding the suffix '-ical', yielding 'balneological'.

Initially it meant 'relating to baths', but over time it evolved to the more specific modern sense 'relating to therapeutic bathing or the medical use of mineral springs'.