Meaning

noun frequent and watery bowel movements; can be a symptom of infection or food poisoning or colitis or a gastrointestinal tumor

originFrom Middle English diaria, from Middle French diarrie (French diarrhée), from Late Latin diarrhoea, from Ancient Greek διάρροια (diárrhoia, “through-flowing”), from διά (diá, “through”) + ῥέω (rhéō, “flow”). By surface analysis, dia- + -rrhea. Spelling later altered to resemble the word's Latin and Greek roots. Displaced native Old English ūtsiht (literally “straining out”).

Etymology from Wiktionary, CC BY-SA 3.0