acuity
uh-KYOO-ih-tee
/əˈkjuːəti/
Sharpness or keenness of thought, vision, or perception.
Refers to spatial or qualitative resolution in sensory systems (e.g., visual acuity) or mental sharpness.
The story behind the word. From Medieval Latin 'acuitas', stemming from Latin 'acuere' (to make sharp) and 'acus' (needle). Related to 'acupuncture' and 'acute'—anything with acuity cut through blur like a sharp needle point.
Word relationships
- keenness: 'Keenness' is a general term, whereas 'acuity' is used more formally in physiological and psychological contexts.
- sharpness: 'Sharpness' can be applied colloquially; 'acuity' carries technical and scientific precision.
- dullness: 'Dullness' denotes a lack of sharpness or sensory responsiveness.
- impairment: 'Impairment' refers to weakened or damaged sensory functioning.
Commonly confused with
- acumen: 'Acumen' refers to business or practical shrewdness, whereas 'acuity' usually refers to sensory sharpness or mental focus.
Word family
- acute (adjective): Sharp, intense, or highly perceptive.
Collocations
- visual acuity
- mental acuity
- auditory acuity
- sharp acuity
Example sentences
- "Standard vision tests measure visual acuity by asking patients to read letters on an eye chart from twenty feet away." Ophthalmology
- "Regular intellectual engagement helps maintain mental acuity well into old age." Cognitive Decline
Memory hook
ACUITY sounds like ACUTE—an acute angle is sharp, so ACUITY is SHARPNESS. Sharp as a needle point (acus).
When not to use
Do not use to describe general intelligence or emotional sensitivity unless referring specifically to precision.
Fun facts
- Eagles have visual acuity roughly four to eight times stronger than that of a human with 20/20 vision!
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