Definition of Opioid Opioid: 1. A synthetic narcotic that resembles the naturally occurring opiates. 2. Any substance that binds to or otherwise affects the opiate receptors on the surface of the cell.
Opioid: 1. A synthetic narcotic that resembles the naturally occurring opiates. 2. Any substance that binds to or otherwise affects the opiate receptors on the surface of the cell.
