Emily Dickinson Lexicon

FIL'TER, n. [Fr. filtre, feutre; Sp. filtro; It. feltro; properly felt, fulled wool, lana coacta, this being used for straining liquors.]

A strainer; a piece of woolen cloth; paper or other substance, through which liquors are passed for defecation. A filter may be made in the form of a hollow inverted cone, or by a twist of thread or yarn, being wetted and one end pot in the liquor and the other suffered to hang out below the surface of the liquor. Porous stone is often used as a filter.