Opioid

//ˈəʊpiɔɪd// noun

noun ·Rare ·Advanced level

Definitions

Noun
  1. 1
    A substance that has effects similar to opium:; Any of the natural substances, such as an endorphin, released in the body in response to pain; an endogenous opioid.

    "Mechoulam concluded that our bodies must produce their own cannabinoids — endogenous molecules that, like the native opioids and nicotinelike molecules our bodies also make, engage the cannabinoid receptors throughout the human body."

  2. 2
    A substance that has effects similar to opium:; Any of a group of synthetic compounds that exhibit similarities to the opium alkaloids that occur in nature.

    "The number of young children in the US who have died from opioid overdoses has increased significantly, according to a new study on accidental poisonings of children 5 and younger."

Example

More examples

"About 77 Americans die each day from an opioid overdose."

Etymology

Attested 1963; from opium + -oid, to distinguish from opiate.

Related phrases

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.