Main Entry: re·hy·drate Pronunciation: (')rE-'hI-"drAt Function: transitive verb Inflected Forms: -drat·ed; -drat·ing : to restore fluid to (something dehydrated); especially: to restore body fluid lost in dehydration to <rehydrate a patient> —re·hy·dra·tion/"rE-"hI-'drA-sh&n/noun