Definitions
1.noun(usually uncountable) The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, the sky.
2.nounThe field or sphere of an activity or interest."the international fashion firmament"
3.nounIn the geocentric Ptolemaic system, the eighth celestial sphere which carried the fixed stars; (by extension) any celestial sphere.
4.noun(obsolete except biblical) The abode of God and the angels; heaven.
5.nounA piece of jewellery worn in a headdress with numerous gems resembling stars in the sky.
6.nounA basis or foundation; a thing which lends strength or support.
7.nounThe act or process of making firm or strengthening.