medical dictionary definition of thirst
Full Definition of THIRST. 1. a: a sensation of dryness in the mouth and throat associated with a desire for liquids; also: the bodily condition (as of dehydration) that induces this sensation b: a desire or need to drink.2. See thirst defined for English-language learners.earn More About THIRST. Thesaurus: All synonyms and antonyms for thirst. Spanish Central: Spanish translation of thirst. Nglish: Translation of thirst for Spanish speakers. Britannica English: Translation of thirst for Arabic speakers. Britannica.com: Encyclopedia article about thirst.