filter

Definitions

• A device which separates a suspended, dissolved, or particulate matter from a fluid, solution, or other substance; any device that separates one substance from another.
• Electronics or software that separates unwanted signals (for example noise) from wanted signals or that attenuates selected frequencies.
• Any item, mechanism, device or procedure that acts to separate or isolate.
• (figurative) self-restraint in speech.
• (mathematics) A non-empty empty upper set (of a partially ordered set) which is closed under binary infima (a.k.a. meets).