opioid Syllabification: (o·pi·oid)Pronunciation: /ˈōpēˌoid/ BiochemistryDefinition of opioid noun an opiumlike compound that binds to one or more of the three opioid receptors of the body. adjective relating to opioid compounds. Origin: 1950s: from opium + -oidopioid in other Oxford dictionaries Definition of opioid in the British & World English dictionary
