Definition of "Winnow" :
noun: the act of separating grain from chaff
"The winnowing was done by women."
verb: blow away or off with a current of air
verb: select desirable parts from a group or list
"Winnow the finalists from the long list of applicants."
verb: separate the chaff from grain by using air currents
"She stood there winnowing grain all day in the field."
verb: blow on
"The wind was winnowing her hair."