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type of hinged sash-window that swings open like doors, early 15c., "hollow molding," probably a shortening of Old French dialectal enchassement "window frame" (Modern French enchâssement), from en- "in," prefix forming verbs, + casse "case, frame" (see case (n.2)) + -ment. Or possibly from Anglo-Latin cassementum, from casse. The "window" sense is from 1550s in English. Old folk etymology tended to make it gazement.
The Irish surname is originally Mc Casmonde (attested from 1429), from Mac Asmundr, from Irish mac "son of" + Old Norse Asmundr "god protector."
a barrier of open-work placed before windows (Prov. 7:6). In Judg. 5:28 the Hebrew word is rendered "lattice," in the LXX. "network," an opening through which cool air is admitted.
earliest form of movable window, wood or metal framed, with hinges or pivots at the upright side of the vertically hung sash, so that it opens outward or inward along its entire length in the manner of a door. One frame, separately movable, of such a window is called a casement sash.