strainer

noun4

1. •
   A device through which a liquid is passed for purification, filtering or separation from solid matter; anything (including a screen or a cloth) used to strain a liquid.
2. •
   A perforated screen or openwork (usually at the end of a suction pipe of a pump), used to prevent solid bodies from mixing in a liquid stream or flowline.
3. •
   One who strains.

   • An important factor with respect to recurrence [of rectal prolapse] is the fact that many of these patients are chronic strainers. — 2008
4. •
   Debris in water that blocks the passage of solid objects.