-rrhoea-rrheacomb. form

Etymology: < post-classical Latin -rrhoea (in e.g. diarrhoea diarrhoea n.) < ancient Greek -ρροια (in e.g. διάρροια diarrhoea n., ἀπόρροια aporrhœa n.) < ῥοία flux, flow < an ablaut variant of the base of ρεῖν to flow (see rheid n.) + the base of -ία -ia suffix¹.First attested in diarrhoea n., a 14th-cent. borrowing of a Latin word of Greek origin, and subsequently likewise in the 16th cent. in gonorrhoea n. Appears in the 17th and 18th centuries in a number of loans and adaptations of Greek words, often immediately via Latin (as e.g. aporrhœa n.), and in increasing numbers throughout the 18th cent. in loans and adaptations of Latin words composed of elements of Greek origin (as e.g. galactorrhoea n., otorrhoea n., etc.). In the 19th cent. also occasionally found in borrowings and adaptations of French and German words ultimately of Greek origin (compare hydrorrhœa n. and stearrhœa n. respectively). Formations within English are found from the late 18th or early 19th cent. Chiefly combining with first elements ultimately of Greek origin, although compare seborrhœa n., with a first element ultimately of Latin origin. Compare French -rrhée (formations in which are found from at least the late 18th cent.), German -rrhoea.