- (v.&a.) The region of the air; the sky or heavens.
- (v.&a.) Fixed foundation; established basis.
- (v.&a.) The orb of the fixed stars; the most rmote of the celestial spheres.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). Firmament. Retrieved September 21, 2026, from http://smartdefine.org/firmament/definitions/2008174 |
| Chicago | Webster's. 2011. "Firmament" http://smartdefine.org/firmament/definitions/2008174 (accessed September 21, 2026). |
| Harvard | Webster's 2011, Firmament, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/firmament/definitions/2008174>. |
| MLA | Webster's. "Firmament" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/firmament/definitions/2008174> |