1. A thin, sharpened side, as of the blade of a cutting instrument.
2. The degree of sharpness of a cutting blade.
3. A penetrating, incisive quality.
4. A slight but noticeable sharpness or harshness.
5. The line of intersection of two surfaces.
6. A rim or brink.
7. The point at which something is likely to begin.
8. The area or part away from the middle; an extremity.
9. A dividing line; a border.