This masculine noun means 'mirror,' appearing once in Job 37:18 as part of a simile describing the sky's appearance. Elihu challenges Job: 'Can you, like him, spread out the skies, hard as a cast metal mirror?' Ancient mirrors were polished metal, not glass, giving them a distinctive bright, hard surface. The comparison suggests both the reflective brilliance of the sky and its seeming solidity—as if the heavens were a firm, beaten metal dome. This image reflects ancient Near Eastern cosmology where the firmament (raqia) was conceived as a solid vault.