The phrase "not living" can refer to anything that is not alive. There are many different words that can be used as synonyms for this phrase, including nonliving, lifeless, inanimate, deceased, expired, and dead. Each of these words has a slightly different connotation and usage, but they all refer to the same basic concept of something that is not living. Some other related terms include inert, motionless, insentient, and ghostly. Whether you are talking about a plant, an animal, or some other object or phenomenon, there are many different terms you can use to describe it as "not living".