(usually countable, literary, also figuratively) The vault of the heavens, where the clouds, sun, moon, and stars can be seen; the heavens, where the clouds, sun, moon, planets, and stars can be seen; the heavens, the sky , the sky.

Of, belonging to, or relating to the firmament or heavens; celestial. / (rare) Of, belonging to, or relating to support or strengthening.

plural of firmament

In the direction of the sky or the heavens.