“Winnow” stems from the Old English word “windwian,” which is also the root of the word “wind,” as in “a gust of air.” While the current, most common usage relates to sorting out the best and most useful items from a group, all of the definitions start with the wind. The original usage related to the wind blowing, and that turned into blowing air through grain in order to remove the chaff from the wheat. That definition was eventually extended as a metaphor for the current usage of today.