When something is "not service" it means that it isn't functioning or working properly. There are many synonyms for this phrase, including out of order, defective, broken, malfunctioning, nonfunctional, inoperable, and unusable. Each of these words suggests a problem with a particular item or device, and can be used to describe things like a car, computer, printer, or piece of machinery that needs repair. Additionally, if something is not serviceable, it may be referred to as faulty, impaired, damaged, flawed or unreliable. Regardless of the specific synonym used, when something is "not service," it should be repaired or replaced to ensure optimal performance and safety.