Definition of codeine in US English:



  • A sleep-inducing and analgesic drug derived from morphine.

    An alkaloid; chemical formula: C₁₈H₂₁NO₃

    • ‘Opiates - drugs like codeine and morphine that contain or are derived from opium - are considered low-grade narcotics.’
    • ‘The question of interest is not so much whether they are potent analgesics compared with codeine but, rather, which painful conditions they are effective in.’
    • ‘You should take warm baths and take painkillers if necessary, but avoid painkillers containing codeine as these often have side effects.’
    • ‘If this does not work the second step is to continue these drugs and add a weak synthetic opium imitator such as codeine or oxycodone.’
    • ‘In addition, staff were concerned that pain might be undertreated once acetaminophen with codeine was the only analgesic used for pain management.’


Mid 19th century: from Greek kōdeia ‘poppy head’ + -ine.