Webster's Revised Unabridged Dictionary · 1913

Winnow

Winnow (win"no) , transitive verb

[Old English windewen, winewen, Anglo-Saxon windwian; akin to Gothic winpjan (in comp.), winpi-skauro a fan, Latin ventilare to fan, to winnow; compare Latin wannus a fan for winnowing, German wanne, Old High German wanna. r131. See Wind moving air, and compare Fan., n., Ventilate.]

1.
To separate, and drive off, the chaff from by means of wind; to fan; as, to winnow grain.
Ho winnoweth barley to-night in the threshing floor. — Ruth. iii. 2
2.
To sift, as for the purpose of separating falsehood from truth; to separate, as bad from good.
Winnow well this thought, and you shall find This light as chaff that flies before the wind. — Dryden
3.
To beat with wings, or as with wings. [Poetic]
Now on the polar winds; then with quick fan Winnows the buxom air. — Milton

Winnow , intransitive verb

To separate chaff from grain.
Winnow not with every wind. — Ecclus. v. 9