Source : Webster's Revised Unabridged Dictionary (1913)

Duster \Dust"er\, n.
   1. One who, or that which, dusts; a utensil that frees from
      dust. Specifically:
      (a) (Paper Making) A revolving wire-cloth cylinder which
          removes the dust from rags, etc.
      (b) (Milling) A blowing machine for separating the flour
          from the bran.

   2. A light over-garment, worn in traveling to protect the
      clothing from dust. [U.S.]

Source : WordNet®

duster
     n 1: a windstorm that lifts up clouds of dust or sand; "it was
          the kind of duster not experienced in years" [syn: {dust
          storm}, {sandstorm}, {sirocco}]
     2: a loose coverall (coat or frock) reaching down to the ankles
        [syn: {gaberdine}, {gabardine}, {smock}, {dust coat}]
     3: a piece of cloth used for dusting [syn: {dustcloth}, {dustrag}]
     4: a pitch thrown deliberately close to the batter