Cāse'ment, n.

(Synop., § 130), n. [O. Eng. casement, a concave molding, formed from case, frame; case of a door, equivalent to frame for a door, Fr. châssis de fenêtre, window-frame. The O. Fr. casement, chasement, land held in fee, equivalent to L. Lat. casamentum, and the It. casamento, a large house, are different words.] (Arch.) A glazed frame or sash, opening on hinges, which are affixed to the upright sides of the frame into which it is fitted.

They beat at the crazy casement. Longfellow.