Sharpness or acuteness, as of a needle, wit, etc.
Acuteness; sharpness.
[Latin] Sharpness; distinctness.
Sharpness or clearness, especially of vision.
Acuteness or keenness, especially of vision. In ophthalmic practice the visual acuity is measured by test letters, each of which subtends an angle of 5' at the eye. [Lat.]