1. Sharpness; but seldom used in this literal sense, as applied to material things.
2. Figuratively, the faculty of nice discernment or perception; applied to the senses, or the understanding. By an acuteness of feeling, we perceive small objects or slight impressions; by an acuteness of intellect, we discern nice distinctions.
3. Sharpness, or elevation of sound, in rhetoric or music.
4. Violence of a disease, which brings it speedily to a crisis.