acuity
/əˈkjʊətɪ/noun
mass noun
- sharpness or keenness of thought, vision, or hearing（思想、视力或听力的）尖锐, 敏锐; 敏度：
intellectual acuity
智力敏锐
visual acuity.
视力（或视敏度）。
词源
late Middle English: from Old French acuite or medieval Latin acuitas, from Latin acuere 'sharpen' （see ACUTE）.