knife

noun

1. A utensil or a tool designed for cutting, consisting of a flat piece of hard material, usually steel or other metal (the blade), usually sharpened on one edge, attached to a handle. The blade may be pointed for piercing.

   “He was looking for a knife to chop some steak.”

   “Jeff was bent low over the backboard, working with the knife, a steady sawing motion, his shirt soaked through with sweat.”

2. A weapon designed with the aforementioned specifications intended for slashing or stabbing but too short to be called a sword; a dagger.
3. Any blade-like part in a tool or a machine designed for cutting, such as that of a chipper.

verb

1. (transitive)To cut with a knife.
2. (transitive)To use a knife to injure or kill by stabbing, slashing, or otherwise using the sharp edge of the knife as a weapon.

   “She was repeatedly knifed in the chest.”

   “One day his sergeant began to cane him, on which, seizing his knife, he knifed the sergeant : he knifed the privates : he knifed until he was finally overpowered, and, brought before a court-martial, was condemned to fifteen years at the galleys.”

   “The plane has been hijacked. They've already knifed a guy.”

   “Naw, they found him in the pissery of some gin mill near the Mohawk West terminal—he'd been knifed.”

3. (intransitive)To cut through as if with a knife.

   “The boat knifed through the water.”

4. (transitive)To betray, especially in the context of a political slate.
5. (transitive)To positively ignore, especially in order to denigrate; compare cut.