I. ˈō-pē-ˌȯid adjective
Date: 1967
1. : possessing some properties characteristic of opiate narcotics but not derived from opium
2. : of, involving, or induced by an opioid
II. noun
Date: 1967
1. : any of a group of endogenous neural polypeptides (as an endorphin or enkephalin) that bind especially to opiate receptors and mimic some of the pharmacological properties of opiates — called also opioid peptide
2. : a synthetic drug possessing narcotic properties similar to opiates but not derived from opium ; broadly : opiate 1a