sharpness; acuteness; keenness: acuity of vision; acuity of mind.

1375–1425; late Middle English acuite < Old French < Medieval Latin, Late Latin acuitās, equivalent to Latin acu(ere) to sharpen or acū(tus) sharpened (see acute) + -itās -ity

hyperacuity, noun
nonacuity, noun Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To acuity
World English Dictionary
acuity (əˈkjuːɪtɪ)
1.  keenness or acuteness, esp in vision or thought
2.  the capacity of the eye to see fine detail, measured by determining the finest detail that can just be detected
[C15: from Old French, from Latin acūtusacute]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

1540s, from M.Fr. acuité, from M.L. acuitatem (nom. acuitas) "sharpness," from L. acus "needle," acuere "to sharpen," from PIE base *ak- "rise to a point, be sharp" (see acrid).
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

acuity a·cu·i·ty (ə-kyōō'ĭ-tē)
Sharpness, clearness, and distinctness of perception or vision.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Example sentences
There may also have been selection for other factors, such as mental acuity.
While that sentiment may seem bleak, it is only because the author approaches
  the nature of fear with uncommon acuity and insight.
Some have hospital-style triage units to rank the acuity of students who cross
  their thresholds.
In fact, he tells me, his mental acuity has grown stronger over the past year.
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature