Толковый словарь английского языка Oxford English Reference - winnow

v.tr. 1 blow (grain) free of chaff etc. by an air-current. 2 (foll. by out, away, from, etc.) get rid of (chaff etc.) from grain. 3 a sift, separate; clear of refuse or inferior specimens. b sift or examine (evidence for falsehood etc.). c clear, sort, or weed out (rubbish etc.). 4 poet. a fan (the air with wings). b flap (wings). c stir (the hair etc.). Derivatives winnower n. (in senses 1, 2). Etymology: OE windwian (as WIND(1))