re·​tar·​da·​tion | \ ˌrē-ˌtär-ˈdā-shən How to pronounce retardation (audio) , ri- \

Definition of retardation

1 : an act or instance of retarding
2 : the extent to which something is retarded
3 : a musical suspension specifically : one that resolves upward
4a(1) : an abnormal slowness of thought or action psychomotor retardation
(2) now often offensive : intellectual disability
b : slowness in development or progress fetal growth retardation

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Synonyms & Antonyms for retardation



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Examples of retardation in a Sentence

The child suffered severe mental retardation. The chemical induced a retardation of cell growth.
Recent Examples on the Web The Vantage’s brake pedal has a nice firm weight but little travel, retardation being down to pressure rather than movement. Mike Duff, Car and Driver, "2019 Aston Martin Vantage: We Slide Behind the Wheel of a Prototype," 28 Feb. 2018 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)., "America needs a new 'dreadnought strategy'," 28 July 2017 At the end Austen had psychomotor retardation and could barely move. Rene Chun, Los Angeles Magazine, "Inside the Los Angeles Clinic That Uses Ketamine to Treat Depression," 19 June 2017 The autism spectrum refers to a broad range of symptoms, from the relatively mild social awkwardness of Asperger's syndrome to profound mental retardation, debilitating repetitive behaviors and an inability to communicate. Maggie Fox, NBC News, "Fevers During Pregnancy Raise Autism Risk, Study Shows," 13 June 2017 J.D.S. suffered from cerebral palsy, epilepsy and mental retardation. Gray Rohrer,, "Scott signs bill giving $1M to Orlando woman raped in group home," 2 June 2017 The survey found that the majority of respondents would elect to screen for diseases like mental retardation, blindness, cancer and heart disease, and a hefty minority (20%) would screen for a disease that would result in death by the age of 50. Daniel Macarthur, WIRED, "The market for designer babies," 1 Feb. 2009 The front wheels threaten to lock up under what feels like normal levels of retardation at low speeds. Mike Duff, Car and Driver, "2018 Morgan 4/4," 30 June 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'retardation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of retardation

15th century, in the meaning defined at sense 1

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Time Traveler for retardation

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The first known use of retardation was in the 15th century

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Statistics for retardation

Cite this Entry

“Retardation.” Dictionary, Merriam-Webster, Accessed 19 Apr. 2021.

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More Definitions for retardation



English Language Learners Definition of retardation

old-fashioned + sometimes offensive : an unusual slowness of mental development
formal : an act of slowing down the development or progress of something


re·​tar·​da·​tion | \ ˌrē-ˌtär-ˈdā-shən, ri- How to pronounce retardation (audio) \

Medical Definition of retardation

1a : an abnormal slowness of thought or action psychomotor retardation
b now often offensive : intellectual disability
2 : slowness in development or progress fetal growth retardation

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