'balanoposthitis' originates from New Latin (medical coinage) and ultimately from Greek, specifically the words 'balanos' and 'posthē' and the suffix '-itis', where 'balanos' meant 'acorn' (used for the glans), 'posthē' meant 'foreskin', and '-itis' meant 'inflammation'.

'balanoposthitis' was formed in modern medical New Latin by combining the Greek roots 'balanos' + 'posthē' with the Greek-derived suffix '-itis' and entered English as a technical medical term with little morphological change.

Initially the component roots referred to the anatomical parts ('acorn' for glans and 'posthē' for foreskin); over time the compound came to denote specifically the clinical condition of inflammation involving both the glans and the foreskin.