The thin sharpened side of the blade of a cutting instrument or weapon; opposed to the ‘back’ or blunt side; or to the ‘flat’ or broad surface of…

The acting, striking, or working surface of an implement, tool, or the like; the edge of a knife, sword, etc.; the surface of a tooth.

A sharp edge on an implement, etc., used for cutting, esp. on the blade of a knife or tool.

transferred and figurative, esp. a sharp crest of rock, ice, sand, or the like. Also attributive, as knife-edge ridge.

(a) the blade of a knife; (b) something sharp or pointed; (c) in Mountaineering, a kind of piton (see quot. 1968); also attributive and in other…