acu·​i·​ty | \ ə-ˈkyü-ə-tē How to pronounce acuity (audio) , a- \
plural acuities

Definition of acuity

: keenness of perception hearing acuity mental acuity

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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 Yet works associated with these players bear Mahanthappa's imprint, thanks to the ferocity of his tone and the speed and acuity of his technique. Star Tribune, "New music reviews: Miley Cyrus showcases her rock chops on 'Plastic Hearts'," 17 Dec. 2020 Patients can expect a wide-range of services available for low acuity health issues, minor sports or work related injuries, including on-site immunizations for flu and tetanus, and more., "Community News For The Putnam-Killingly Edition," 18 Dec. 2020 Four weeks after treatment, older mice had similar acuity scores to younger ones. Kelly Servick, Science | AAAS, "Researchers restore lost sight in mice, offering clues to reversing aging," 2 Dec. 2020 Frontline health care workers in high-acuity settings were first in line to receive the vaccine between Dec. 17 and Monday, according to Stanford Medicine’s vaccine distribution dashboard. Vanessa Arredondo,, "Report: Non-clinical workers inoculated at Stanford Medicine after misinformation over ‘excess’ vaccines," 30 Dec. 2020 Still, the improvement in acuity was small, Levin notes. Kelly Servick, Science | AAAS, "Researchers restore lost sight in mice, offering clues to reversing aging," 2 Dec. 2020 Throughout his campaign, Mr. Biden faced persistent doubts about his political acuity and the relevance, in the year 2020, of a set of union-hall-meets-cloakroom political instincts developed mainly in the previous century. Jonathan Martin, New York Times, "How Joe Biden Won the Presidency," 7 Nov. 2020 More to the point, the bar for mental acuity and stability for Presidents has lowered along with much else in the past four years. Jeannie Suk Gersen, The New Yorker, "We May Need the Twenty-fifth Amendment if Trump Loses," 26 Oct. 2020 Persistent questions about her mental acuity — particularly her short-term memory — haven’t helped, with staffers frequently having to clarify statements that Feinstein has made to reporters. Erika D. Smith Columnist, Los Angeles Times, "Column: Should California’s next U.S. senator be Black or Latino? Both if Feinstein quits," 10 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'acuity.' 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 acuity

circa 1549, in the meaning defined above

History and Etymology for acuity

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

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Time Traveler for acuity

Time Traveler

The first known use of acuity was circa 1549

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Statistics for acuity

Last Updated

20 Feb 2021

Cite this Entry

“Acuity.” Dictionary, Merriam-Webster, Accessed 26 Feb. 2021.

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More Definitions for acuity



English Language Learners Definition of acuity

formal : the ability to see, hear, or understand something easily


acu·​ity | \ ə-ˈkyü-ət-ē How to pronounce acuity (audio) \
plural acuities

Medical Definition of acuity

: keenness of sense perception acuity of hearing — see visual acuity

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