retardation

noun

ˌrē-ˌtär-ˈdā-shən How to pronounce retardation (audio)
Definition of retardationnext
as in deceleration
a usually gradual decrease in the pace or level of activity of something scientists discovered that they could achieve the retardation of light if they shined it through a variety of substances

Synonyms & Similar Words

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Antonyms & Near Antonyms

Example Sentences

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.
Recent Examples of retardation The Everrati's left pedal operates pads on discs in the normal fashion, but the motors also give powerful regenerative retardation when the accelerator is lifted. — Mike Duff, Car and Driver, 18 June 2021 The policy of retardation of submarine technology ended right after the beginning of the Anglo-German naval race (marked by the German Naval Laws of 1898 and 1900). — chicagotribune.com, 28 July 2017 At the end Austen had psychomotor retardation and could barely move. — Rene Chun, Los Angeles Magazine, 19 June 2017 The degree of retardation is usually mild, but can be moderate to severe. — Mark Cohen, Discover Magazine, 4 Apr. 2012
Recent Examples of Synonyms for retardation
  1. deceleration
  2. decline
  3. slowdown
  4. braking
  5. drop
  6. slump
Noun
  • Ad impressions delivered across the family of apps increased 10%, a sequential deceleration.
    — Zev Fima, CNBC, 22 Oct. 2026
  • Analysts had predicted that the third-quarter luxury earnings would be challenging, notably due to a sequential deceleration in China.
    — Laure Guilbault, Vogue, 22 Oct. 2026
Definition of deceleration
Noun
  • Among the relics of its decline is a hulking complex of rusted pipes, towers and conveyor belts in Delano, just five miles north of the McFarland chipping yard.
    — Los Angeles Times, Los Angeles Times, 21 Oct. 2026
  • The stock was down -7% in premarket trading Wednesday, to under $64/share, a decline of nearly 30% year-to-date to the lowest point since August 2024.
    — Todd Spangler, Variety, 21 Oct. 2026
Definition of decline
Noun
  • The chief executive has called for a coordinated slowdown in AI development.
    — Los Angeles Times, Los Angeles Times, 27 Oct. 2026
  • But the slowdown has coincided with AI becoming a more difficult political sell.
    — Luke Fountain, CNBC, 27 Oct. 2026
Definition of slowdown
Noun
  • Video of the Woodland incident shows a black SUV braking and veering left before a person near the front of the vehicle tumbled to the pavement, as observers blew whistles to warn of approaching agents, according to footage.
    — Sacbee.com, Sacbee.com, 20 Oct. 2026
  • These rocket engines dramatically improve acceleration, top speed, braking & cornering.
    — Mike Wall, Space.com, 16 Oct. 2026
Definition of braking
Noun
  • To Nothing’s credit, the case gets IPX2 ingress protection, so a drop of rain now and then shouldn’t kill it.
    — Mark Knapp, PC Magazine, 24 Oct. 2026
  • Vaibhav steps into the India lineup in place of Ishan Kishan who has a groin injury and will bat at first drop unless India chooses to match him in an all left hand opening partnership with Abhishek Sharma.
    — ABC News, ABC News, 24 Oct. 2026
Definition of drop
Noun
  • Chief Financial Officer Shiv Verma told CNBC event contracts on crypto movements did well in the quarter, offering investors another way to express a view on crypto despite the slump in prices and spot trading.
    — Tanaya Macheel, CNBC, 27 Oct. 2026
  • There's a kernel of truth to it; Ohtani was clearly limited by several injuries down the stretch, with a lengthy slump accompanying an increase in chase rate and swing and miss.
    — Ian Miller OutKick, FOXNews.com, 23 Oct. 2026
Definition of slump

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retardant
retardation
retardations
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Cite this Entry

“Retardation.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/retardation. Accessed 28 Oct. 2026.

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More from Merriam-Webster on retardation

Britannica.com: Encyclopedia article about retardation

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