Knife, v. t. Fig.: To stab in the back; to try to defeat by underhand means, esp. in politics; to vote or work secretly against (a candidate of one's own party). [Slang, U. S.]

Knife (?), n.; pl. Knives (#). [OE. knif, AS. cnīf; akin to D. knijf, Icel. knīfr, Sw. knif, Dan. kniv.] 1. An instrument consisting of a thin blade, usually of steel and having a sharp edge for cutting, fastened to a handle, but of many different forms and names for different uses; as, table knife, drawing knife, putty knife, pallet knife, pocketknife, penknife, chopping knife, etc..

2. A sword or dagger.

The coward conquest of a wretch's knife.

Knife, v. t. [imp. & p. p. Knifed (?); p. pr. & vb. n. Knifing (?).] 1. (Hort.) To prune with the knife.

2. To cut or stab with a knife. [Low]

Knife, v. t. Fig.: To stab in the back; to try to defeat by underhand means, esp. in politics; to vote or work secretly against (a candidate of one's own party). [Slang, U. S.]

• A utensil consisting of a sharpened piece of hard material such as steel or other metal, ceramic, glass or stone, usually attached to a handle, that is formed in a manner that allows for cutting softer materials, especially meat or other food. There is often a point for piercing.
  
• A weapon designed with the aforementioned specifications intended for slashing and/or stabbing and too short to be called a sword. A dagger.
  
• to use a knife to injure or kill by stabbing, slashing, or otherwise using the sharp edge of the knife as a weapon