BIBLE DICTIONARY
Firmament

The expanse of heaven, meaning, depending on the context, the atmosphere or the sidereal heavens. It is the KJV English translation of a Hebrew word meaning expanse, and is spoken of in Gen. 1; Ps. 19: 1; Moses 2; Abr. 4; Abr., fac. 1, fig. 12; see esp. Abr. 4: 7-8, 20.