blade

Definitions

General English

General Science

  • noun a flattened part of a propeller, rotor or wind turbine

Agriculture

  • noun a thin flat leaf, e.g. a leaf of a grass, iris or daffodil
  • noun the sharp flat cutting part of a knife, mowing machine, etc

Cars & Driving

  • noun a straight, narrow flat part, such as the end of a screwdriver, the part of a windscreen wiper in contact with the windscreen, or one of the vanes of a rotor or impeller

Cricket

  • noun the solid part of the bat, as distinguished from the handle, with which the ball is struck.
    See bat
  • noun the bat itself
    Citation ‘St. Hill did not hook by preference to long leg … He seemed merely to step inwards and swish the blade across the flight so that when it hit the ball it was pointing at the bowler’ (James 1963)

Electronics

  • A flat moving conductor used in a switch.

Food

  • noun a long thin flat part of some tools or machines, e.g. of a food mixer

Slang

  • noun a knife, particularly when used for protective or offensive purposes

Travel

  • noun a sharp metal strip attached to a boot to make an ice skate.

Origin & History of “blade”

The primary sense of blade appears to be ‘leaf’ (as in ‘blades of grass’, and German blatt ‘leaf’). this points back to the ultimate source of the word, the Germanic stem *bhlō-, from which English also gets bloom, blossom, and the now archaic blow ‘come into flower’. However, the earliest sense recorded for Old English blæd was the metaphorical ‘flattened, leaflike part’, as of an oar, spade, etc. The specific application to the sharp, cutting part of a sword or knife developed in the 14th century.
http://www.dictionarycentral.com/definition/blade.html