acuity

noun

acu·​i·​ty ə-ˈkyü-ə-tē How to pronounce acuity (audio)
a-
plural acuities
: keenness of perception
hearing acuity
mental acuity

Did you know?

Do you have acuity or sensitivity?

Acuity is nearly synonymous with at least one sense of sensitivity, yet, as is so often the case with closely related words, there are subtle differences worth observing before you substitute one of these words for the other. Acuity does refer to a form of sensitivity, but it is most often applied to the perceptual senses (as in “visual acuity” or “auditory acuity”). It is also frequently used in reference to the intellect (as in “mental acuity”). Sensitivity has a broader range of meanings than acuity does, including “the capacity of being easily hurt.” It may be used of inanimate objects such as radios (“the sensitivity of the instruments was carefully calibrated”), a context in which acuity is unusual.

Examples of acuity in a Sentence

a worrisome deterioration in the acuity of his hearing over the years
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.
The former president's decision to seek a second term, only to belatedly withdraw amid questions about his mental acuity, has contributed to the Democrats' current nadir. Susan Page, USA Today, 31 July 2025 But former President Joe Biden's waning acuity and the disproportionate impact of inflation and the coronavirus pandemic closures on the county's crucial tourism industry were on voters' minds, too, Frostman said. Molly Beck, jsonline.com, 15 July 2025 David Weigel: Right now, Oversight is dealing with the Republican investigation of Biden’s acuity and use of an autopen — Trump waiving executive privilege so that Biden officials can be interviewed by the committee. David Weigel, semafor.com, 27 June 2025 The disastrous debate performance pushed questions about his age and mental acuity to the forefront, ultimately leading Biden to withdraw from the presidential race. Matt Brown, Los Angeles Times, 5 June 2025 See All Example Sentences for acuity

Word History

Etymology

Middle English acuite "sharpness, acridity," borrowed from Middle French acuité, borrowed from Medieval Latin acuitāt-, acuitās, from Latin acu-, stem of acuere "to sharpen" + -itāt-, -itās -ity — more at acute

First Known Use

circa 1549, in the meaning defined above

Time Traveler
The first known use of acuity was circa 1549

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Cite this Entry

“Acuity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/acuity. Accessed 6 Aug. 2025.

Kids Definition

acuity

noun
acu·​ity ə-ˈkyü-ət-ē How to pronounce acuity (audio)
: sharpness of perception

Medical Definition

acuity

noun
acu·​ity ə-ˈkyü-ət-ē How to pronounce acuity (audio)
plural acuities
: keenness of sense perception
acuity of hearing
see visual acuity

More from Merriam-Webster on acuity

Last Updated: - Updated example sentences
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