The Collaborative International Dictionary of English v.0.48:

Knife \Knife\ (n[imac]f), n.; pl. Knives (n[imac]vz). [OE.
   knif, AS. cn[imac]f; akin to D. knijf, Icel. kn[imac]fr, 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..
      [1913 Webster]

   2. A sword or dagger.
      [1913 Webster]

            The coward conquest of a wretch's knife. --Shak.
      [1913 Webster]

   Knife grass (Bot.) a tropical American sedge (Scleria
      latifolia), having leaves with a very sharp and hard
      edge, like a knife.

   War to the knife, mortal combat; a conflict carried to the
      last extremity.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Knife \Knife\, v. t. [imp. & p. p. Knifed; p. pr. & vb. n.
   Knifing.]
   1. (Hort.) To prune with the knife.
      [1913 Webster]

   2. To cut or stab with a knife. [Low]
      [1913 Webster]

   3. 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.]
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

knife
    n 1: edge tool used as a cutting instrument; has a pointed blade
         with a sharp edge and a handle
    2: a weapon with a handle and blade with a sharp point
    3: any long thin projection that is transient; "tongues of flame
       licked at the walls"; "rifles exploded quick knives of fire
       into the dark" [syn: tongue, knife]
    v 1: use a knife on; "The victim was knifed to death" [syn:
         knife, stab]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "knife":
   ax, barong, bayonet, blade, bolo, bowie, bowie knife, cold steel,
   cut, cutlery, cutter, dagger, dining utensils, dirk, edge tool,
   edge tools, flat silver, flatware, forks, gravity knife,
   hollow ware, impale, knives, lance, machete, naked steel, parang,
   pierce, pigsticker, play dirty pool, play one false, plunge in,
   point, poniard, prove false, puncturer, run through, saber,
   sharpener, silver, silver plate, silverware, slash, spear, spike,
   spit, spoons, stab, stainless-steel ware, steel, stick, stiletto,
   switchblade, switchblade knife, sword, tablespoon, tableware,
   teaspoon, toad sticker, transfix, transpierce, whittle, wound



Easton's 1897 Bible Dictionary:

Knife
   (1.) Heb. hereb, "the waster," a sharp instrument for
   circumcision (Josh. 5:2, 3, lit. "knives of flint;" comp. Ex.
   4:25); a razor (Ezek. 5:1); a graving tool (Ex. 20:25); an axe
   (Ezek. 26:9).

     (2.) Heb. maakeleth, a large knife for slaughtering and
   cutting up food (Gen. 22:6, 10; Prov. 30:14).

     (3.) Heb. sakkin, a knife for any purpose, a table knife
   (Prov. 23:2).

     (4.) Heb. mahalaph, a butcher's knife for slaughtering the
   victims offered in sacrifice (Ezra 1:9).

     (5.) Smaller knives (Heb. ta'ar, Jer. 36:26) were used for
   sharpening pens. The pruning-knives mentioned in Isa. 18:5 (Heb.
   mizmaroth) were probably curved knives.