The term 'Narcotic Painkiller' can be summarized as an OPIATE, which is a six-letter word. Opiates are a type of drug derived from the opium poppy plant and are used to relieve pain. They are highly addictive and can have serious side effects, including respiratory depression, constipation, and even death. Narcotic painkillers are often prescribed by doctors to treat severe pain, but they can also be abused for recreational purposes.