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
Noun
New Jersey provides a limit of a five-day supply of opioids to stabilize chronic pain and in Pennsylvania the limit is seven days and other states have no limits, Turner said. USA TODAY, 24 Apr. 2024 Other possible treatments include an opioid injection. Brenton Blanchet, Peoplemag, 22 Apr. 2024 And those positive outcomes were greater than those associated with nonpharmacological treatments (exercise therapy, yoga, massage therapy, spinal manipulation, acupuncture, cognitive behavioral therapy), opioid therapy, and lumbar spine surgery. Deborah Balthazar, STAT, 12 Apr. 2024 There are several excellent medications for opioid use disorder that dramatically reduce cravings and subsequent use. Teri Sforza, Orange County Register, 9 Apr. 2024 Second, much of the reduction in life expectancies for poor Americans is related to the opioid crisis, which primarily impacts Americans under 65. Karl W. Smith, The Mercury News, 5 Apr. 2024 Without medical treatment, a person must consistently use opioids to curb the incredibly painful, and sometimes deadly, opioid withdrawal. Jim Vargas, San Diego Union-Tribune, 2 Apr. 2024 The following year, a nurse at the facility pleaded guilty to tampering with the fentanyl meant for the women’s procedures, having replaced the opioid with saline. Dr. Sharon Malone, TIME, 9 Apr. 2024 And only 1 in 5 people diagnosed with opioid use disorder take these medications. Teri Sforza, Orange County Register, 9 Apr. 2024
Adjective
Their expansion reflects a growing awareness that many survivors of opioid addiction and those who struggled with substance use during the pandemic are now enrolling in pursuit of a fresh start. Leah Fabel, The Christian Science Monitor, 8 Apr. 2024 The opioid crisis in the United States has been responsible for almost 645,000 deaths over the last two decades. Berkeley Lovelace Jr., NBC News, 4 Apr. 2024 The opioid crisis in the United States has led to countless lives ruined due to addiction, and millions of lives lost due to overdose. Amber Smith, Discover Magazine, 3 Apr. 2024 Treatment for opioid addiction is increasing, except in the young Poison control center cases involving tianeptine exposure jumped from 11 total cases between 2000 and 2013 to 151 cases in 2020 alone, according to the U.S. Food and Drug Administration. Nathan Smith, ABC News, 2 Apr. 2024 Drug overdose deaths, largely caused by the synthetic opioid drug fentanyl, reached record highs in the United States in 2021. Mike Baker, New York Times, 1 Apr. 2024 Naltrexone, used alone, was originally approved by the FDA as a treatment for opioid addiction and alcohol dependence. David Snyder, Verywell Health, 30 Mar. 2024 Andrew Kolodny, a Brandeis University opioid policy researcher and founder of activist group Physicians for Responsible Opioid Prescribing, told STAT that the organization considered this route as well, amid mounting frustration with the agency’s opioid crisis response. Sarah Owermohle, STAT, 28 Mar. 2024 Though rare, people can die from opioid withdrawal syndrome. Lauren Peace, CNN, 27 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'opioid.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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 28 Apr. 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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!