strainer

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One that strains, as a device used to separate liquids from solids.
• noun An apparatus for tightening, stretching, or strengthening.

from The Century Dictionary.

• noun One who or that which strains.
• noun A stretcher or tightener: as, a strainer for wire fences.
• noun Any utensil for separating small solid particles from the liquid that contains them, either to preserve the solid objects or to clarify the liquid, or for both purposes.
• noun In carriage-building: A reinforcing strip or button at the back of a panel.
• noun Canvas glued to the back of a panel to prevent warping or cracking. Also called stretcher.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who strains.
• noun 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun 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; any device functioning as a sieve or filter - in special, 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.
• noun One who strains.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a filter to retain larger pieces while smaller pieces and liquids pass through