blade

n. edge (of a knife); cutting portion of a razor; thin leaf; paddle; bat, racquet; propeller

A blade is the flat part of a tool, weapon, or machine (such as a fan) that normally has a cutting edge and/or pointed end typically made of a metal, most recently, steel intentionally used to cut, stab, slice, throw, thrust, position and/or place (an example of this is razor wire), shoot (an example of this is the ballistic knife) or strike an animate or inanimate object.
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Noun
1. especially a leaf of grass or the broad portion of a leaf as distinct from the petiole
(synonym) leaf blade
(hypernym) leaf, leafage, foliage
2. a dashing young man; "gay young blades bragged of their amorous adventures"
(hypernym) young person, youth, younker, spring chicken
3. something long and thin resembling a blade of grass; "a blade of lint on his suit"
(hypernym) ribbon, thread
4. a cutting or thrusting weapon with a long blade
(synonym) sword, brand, steel
(hypernym) weapon, arm, weapon system
(hyponym) backsword
5. a cut of beef from the shoulder blade
(hypernym) cut of beef
(part-holonym) chuck
6. a broad flat body part (as of the shoulder or tongue)
(hypernym) structure, anatomical structure, complex body part, bodily structure, body structure
(hyponym) vane, web
7. the part of the skate that slides on the ice
(hypernym) runner
(part-holonym) ice skate
8. flat surface that rotates and pushes against air or water
(synonym) vane
(hypernym) rotating mechanism
(hyponym) fan blade
(part-holonym) propeller, propellor
9. the flat part of a tool or weapon that (usually) has a cutting edge
(hypernym) cutting implement
(hyponym) knife blade
(part-holonym) ax, axe
(part-meronym) knife edge, cutting edge

(v. t.)
To furnish with a blade.
  

(v. i.)
To put forth or have a blade.
  

(n.)
The scapula or shoulder blade.
  

(n.)
The principal rafters of a roof.
  

(n.)
The four large shell plates on the sides, and the five large ones of the middle, of the carapace of the sea turtle, which yield the best tortoise shell.
  

(n.)
The cutting part of an instrument; as, the blade of a knife or a sword.
  

(n.)
The broad part of an oar; also, one of the projecting arms of a screw propeller.
  

(n.)
Properly, the leaf, or flat part of the leaf, of any plant, especially of gramineous plants. The term is sometimes applied to the spire of grasses.
  

(n.)
A sharp-witted, dashing, wild, or reckless, fellow; -- a word of somewhat indefinite meaning.
  

applied to the glittering point of a spear (Job 39:23) or sword (Nah. 3:3), the blade of a dagger (Judg. 3:22); the "shoulder blade" (Job 31:22); the "blade" of cereals (Matt. 13:26).