Emily Dickinson Lexicon

SCREEN, n. [Fr. ecran. This word is evidently from the root of L. cerno, excerno, Gr. κρινω, to separate, to sift, to judge, to fight, contend, skirmish; Sp. harnero, a sieve. The primary sense of the root is to separate, to drive or force asunder, hence to sift, to discern, to judge, to separate or cut off danger.]

1. Any thing that separates or cuts off inconvenience, injury or danger; and hence, that which shelters or protects from danger, or prevents inconvenience. Thus a screen is used to intercept the sight, to intercept the heat of fire or the light of a candle. Some ambitious men seem as screens to princes in matters of danger and envy. – Bacon
2. A riddle or sieve.