the act of separating grain from chaff; "the winnowing was done by women" remove by a current of air; "winnow chaff" treat by exposure to a current of air so that waste matter is eliminated; "winnow grain" separate from chaff; "She stood there winnowing grain all day in the field" blow on; "The wind was winnowing her hair
To fan; set in motion by means of wind; specifically, to expose (grain) to a current of air in order to separate and drive off chaff, refuse particles, etc
Figuratively, to subject to a process analogous to the winnowing of grain; to separate into parts according to kind; to sift; to analyze or scrutinize carefully; to examine; to test
If you winnow a group of things or people, you reduce its size by separating the ones that are useful or relevant from the ones that are not. Administration officials have winnowed the list of candidates to three. to make a list, group, or quantity smaller by getting rid of the things that you do not need or want = whittle down