D defs.my
Entry 3 senses Webster, 1913

Firmament

· Fir·ma·ment · IPA /ˈfɝməmənt/
01 n. Fixed foundation; established basis.
  1. 1.
    Fixed foundation; established basis.[Obs.]
    “Custom is the . . . firmament of the law.” Jer. Taylor.
  2. 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.
  3. 3.
    The orb of the fixed stars; the most remote of the celestial spheres.(Old Astron.)