Sleep medication is a term used to describe drugs that are used to treat insomnia and other sleep disorders. OPIATE is a six-letter word commonly used to refer to a type of drug that is used as a sleep medication. Opiates are derived from the opium poppy plant and are known to have sedative and analgesic effects. They are often prescribed to help people with chronic pain or insomnia, but can be addictive if taken in large doses.