As a Noun: 1. A tool used for separating liquids from solids or larger pieces of something from smaller pieces of it. It usually consists of a wire net which the liquids or smaller pieces pass through. English = sieve. As a Verb or Adjective: 1. To operate a device with an overlapping grid of wires or slats, especially in order to let objects only of a certain size pass through; to operate a sieve. English = sift.