plural extinctions
1
a
: the act of making extinct or causing to be extinguished
gradual extinction of the national debt
b
: the condition or fact of being extinct
also : the process of becoming extinct
attempting to save a species from extinction
… at least 17 species of the island's largest mammals, birds, and reptiles were lost in a wave of extinctions that occurred about 1,000 years ago. Pamela S. Cubberly
Now, more than 40 percent of the world's 7,000 or so languages are thought to be at risk of extinction, some with just a handful of elderly native speakers left. Benjamin Plackett
see also mass extinction
2
: the process of eliminating or reducing a conditioned (see conditioned sense 2) response by not reinforcing it
When a rat in a Skinner box presses a lever, a tone sounds momentarily, followed shortly by delivery of food. … After the animal has been conditioned in this way, the experimenter begins extinction, so that when the rat presses the lever neither the tone nor the food appears. Rita L. Atkinson et al.

Examples of extinction in a Sentence

the extinction of all life in the region the extinction of many old traditions Mass extinctions of prehistoric animals are known to have occurred.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
According to an assessment by the U.S. Fish and Wildlife Service, the Western monarch population has plummeted by more than 95% since the 1980s, and has a 99% chance of extinction by 2080. Fidel Martinez, Los Angeles Times, 20 Dec. 2024 Like mammoths, mastodons disappeared toward the end of the last ice age, when a series of factors, including climate change and human hunting, drove many large animals to extinction, as Jess Thomson reports for Newsweek. Margherita Bassi, Smithsonian Magazine, 19 Dec. 2024 Living in humans’ backyard has almost driven the Cook Inlet belugas to extinction. Avery Hurt, Discover Magazine, 13 Dec. 2024 The western monarch population has declined by 95% since the 1980s and faces a 99% chance of extinction by 2080, according to data cited by FWS. Austin Corona, The Arizona Republic, 12 Dec. 2024 See all Example Sentences for extinction 

Word History

First Known Use

15th century, in the meaning defined at sense 1a

Time Traveler
The first known use of extinction was in the 15th century

Dictionary Entries Near extinction

Cite this Entry

“Extinction.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/extinction. Accessed 1 Jan. 2025.

Kids Definition

extinction

noun
1
: an act of extinguishing or an instance of being extinguished
2
a
: the state of being extinct
b
: the process of becoming extinct
3
: the process of eliminating or reducing a conditioned response by not providing the stimulus with which it has become associated by conditioning

Medical Definition

extinction

noun
1
: the process of becoming extinct
the extinction of a species
also : the condition or fact of being extinct
2
: the process of eliminating or reducing a conditioned response by not reinforcing it

More from Merriam-Webster on extinction

Last Updated: - Updated example sentences
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