Definition of strainers:
(n) :
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.
(n) :
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.
(n) :
One who strains.
(n) :
Debris in water that blocks the passage of solid objects.