verb

• (transitive, agriculture, literal) To subject (granular material, especially food grain) to a current of air separating heavier and lighter components, as grain from chaff.
  "[W]ind began to winnow the river delta's dried sediments."
• (transitive, figuratively) To separate, sift, analyse, or test by separating items having different values.
  "They winnowed the field to twelve."
• (transitive, literary) To blow upon or toss about by blowing; to set in motion as with a fan or wings.
  "The light snow lay on the narrow and winding path before them, pure as if just fresh winnowed by the wind."
• (intransitive, literary, dated) To move about with a flapping motion, as of wings; to flutter.