Source : Webster's Revised Unabridged Dictionary (1913)

Strainer \Strain"er\, n.
   1. One who strains.

   2. That through which any liquid is passed for purification
      or to separate it from solid matter; anything, as a screen
      or a cloth, used to strain a liquid; a device of the
      character of a sieve or of a filter; specifically, an
      openwork or perforated screen, as for the end of the
      suction pipe of a pump, to prevent large solid bodies from
      entering with a liquid.

Source : WordNet®

strainer
     n : a filter to retain larger pieces while smaller pieces and
         liquids pass through