Other spellings (US) diarrhea Pronunciation (UK) IPA (key): /ˌdaɪ.əˈriː.ə/ Audio (US)(file) Noun Singular diarrhoea Plural diarrhoeas (uncountable) Diarrhoea is an illness where the person's poop or feces are soft like water.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads