firmament

noun

1. 1

   (usually uncountable) The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.

2. 2

   The field or sphere of an activity or interest.

   “the international fashion firmament”

3. 3

   In the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; (by extension) any celestial sphere.

4. 4

   (obsolete except biblical) The abode of God and the angels; heaven.

5. 5

   A piece of jewellery worn in a headdress with numerous gems resembling stars in the sky.

6. 6

   A basis or foundation; a thing which lends strength or support.

7. 7

   The act or process of making firm or strengthening.