1. 成语饿了吃饭，渴了喝水。形容生活必需。例句少不得～，夜住晓行，不在话下。（明·洪楩《清平山堂话本·杨温拦路虎传 Eat when hungry and drink when thirsty; When one is hungry, he eats and when thirsty he drinks.