knife edge

English Thesaurus

1. the sharp cutting side of the blade of a knife (noun.artifact)

hypernym	:	edge,
definition	:	a sharp side formed by the intersection of two surfaces of an object (noun.artifact)

part meronym	:	blade,
definition	:	the flat part of a tool or weapon that (usually) has a cutting edge (noun.artifact)

part meronym	:	edge tool,
definition	:	any cutting tool with a sharp cutting edge (as a chisel or knife or plane or gouge) (noun.artifact)