Fir'ma-ment, n.

n. [Lat. firmamentum, from firmare; Fr. firmament, Pr. firmamen, firmamen, Sp. firmamento, O. It. firmamento. See supra.] 1. Fixed foundation; well-established basis. [Obs.] Custom is the ... firmament of the law. Bp. Taylor. 2. The region of the air; the sky or heavens. And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters. Gen. i. 6. And God said, Let there be lights in the firmament. Gen. i. 14. — In Scripture, the word denotes an expanse, a wide extent; for such is the signification of the Hebrew word, coinciding with regio, region, and reach. The original, therefore, does not convey the sense of solidity, but of stretching, extension; the great arch or expanse over our heads, in which are placed the atmosphere and the clouds, and in which the stars appear to be placed, and are really seen. 3. (Old Astron.) The orb of the fixed stars; the most remote of the celestial spheres.