opioid

1 of 2

noun

opi·​oid ˈō-pē-ˌȯid How to pronounce opioid (audio)
plural opioids
: a natural, semisynthetic, or synthetic substance that typically binds to the same cell receptors as opium and produces similar narcotic effects (such as sedation, pain relief, slowed breathing, and euphoria):
a
or less commonly opioid peptide : any of various of endogenous polypeptides (such as an endorphin or enkephalin) produced by neurons of the peripheral and central nervous system
The people who rated pain the lowest were those whose brains began producing natural painkillers called opioids the fastest …John O'Neil
b
: any of various opiates (such as morphine), semisynthetic opiate derivatives (such as heroin, hydrocodone, or oxycodone), or synthetic preparations (such as fentanyl or methadone) that may be used illicitly for their narcotic properties and are associated with physiological tolerance (see tolerance sense 4a(1)), physical and psychological dependence, or addiction upon repeated or prolonged use
… fentanyl, a synthetic opioid at least 75 times more potent than morphine.Ryan Trimble and Eric S. Peterson
Naltrexone is an opioid antagonist used for the treatment of heroin addiction.Scientific American
The prototypical opioids are morphine and codeine (which is milder than morphine).Harvard Health Letter
When Walker County was identified as the epicenter of Alabama's opioid crisis, it was no surprise to residents who watched as drugs brought death and devastation down upon their families, neighbors and communities.Ashley Remkus

Note: The word opioid was originally used only for morphine-like substances not derived from opium, but it has now become widely accepted as a broader term encompassing any substance—natural or synthetic, opium-derived or not—that binds to opiate cell receptors and induces sedation, analgesia, and euphoria.

opioid

2 of 2

adjective

: possessing narcotic properties characteristic of opiates : of, relating to, involving, or being an opioid
opioid drugs
opioid addiction
endogenous opioid endorphins
opioid cell receptors

Examples of opioid in a Sentence

Recent Examples on the Web
These examples are automatically compiled from online sources to illustrate current usage. Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Noun
At one press conference, a woman claimed her son died of an opioid overdose after initially beginning drug use with marijuana. A.j. Herrington, Forbes, 29 Oct. 2024 Other shareholders filed two lawsuits against Walmart, claiming some current and former directors and officers breached their fiduciary duties and violated federal securities law, also in connection with the company's distribution and dispensing of prescription opioids. Serenah McKay, arkansasonline.com, 22 Oct. 2024
Adjective
For patients with opioid addiction in particular, outpatient treatment with methadone or buprenorphine significantly reduces overdose rates and recurrence of opioid use when compared to no treatment or treatment that did not offer medications for opioid addiction. Zoe Adams, Scientific American, 22 Oct. 2024 The lame duck session could break gridlock that's kept key programs on pandemic preparedness, opioid addiction and the global AIDS epidemic from getting renewed so far this session, Victoria and Peter report. Peter Sullivan, Axios, 15 Oct. 2024 See all Example Sentences for opioid 

Word History

Etymology

Noun

opium + -oid entry 1

Adjective

opium + -oid entry 2

First Known Use

Noun

1957, in the meaning defined above

Adjective

1967, in the meaning defined above

Time Traveler
The first known use of opioid was in 1957

Dictionary Entries Near opioid

Cite this Entry

“Opioid.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/opioid. Accessed 12 Nov. 2024.

Kids Definition

opioid

noun
opi·​oid ˈō-pē-ˌȯid How to pronounce opioid (audio)
: any substance that binds to the same cell receptors as opium, produces similar effects (as sleepiness and pain relief), includes drugs used medically especially as painkillers, is often used illicitly for its narcotic properties, and often causes physical and psychological dependence

Medical Definition

opioid

1 of 2 noun
: a natural, semisynthetic, or synthetic substance that typically binds to the same cell receptors as opium and produces similar narcotic effects (such as sedation, pain relief, slowed breathing, and euphoria):
a
also opioid peptide : any of various of endogenous polypeptides (such as an endorphin or enkephalin) produced by neurons of the peripheral and central nervous system
b
: any of various opiates (such as morphine), semisynthetic opiate derivatives (such as heroin, hydrocodone, or oxycodone), or synthetic preparations (such as fentanyl or methadone) that may be used illicitly for their narcotic properties and are associated with physiological tolerance (see tolerance sense 1), physical and psychological dependence, or addiction upon repeated or prolonged use
… fentanyl, a synthetic opioid at least 75 times more potent than morphine.Ryan Trimble and Eric S. Peterson
The prototypical opioids are morphine and codeine (which is milder than morphine).Harvard Health Letter

Note: The word opioid was originally used only for morphine-like substances not derived from opium, but it has now become widely accepted as a broader term encompassing any substance—natural or synthetic, opium-derived or not—that binds to opiate cell receptors and induces sedation, analgesia, and euphoria.

opioid

2 of 2 adjective
opi·​oid
: possessing narcotic properties characteristic of opiates : of, relating to, involving, or being an opioid
opioid drugs
opioid addiction
endogenous opioid endorphins
opioid cell receptors

More from Merriam-Webster on opioid

Last Updated: - Updated example sentences
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