the world > space > shape > sharpness of edge or point > sharpen (a thing) [verb (transitive)] > sharpen edge (6)
transitive. To cut to a feather-edge, produce a thin edge upon. Also transferred to turn (oneself) sideways.
transitive. To cut (wood, etc.) down gradually to a thin edge. Cf. feather-edged, adj.
transitive to give a fine edge to; to sharpen.