Subcelestial, a term used to describe things below the heavens or the celestial bodies such as stars, planets, and galaxies. Some antonyms for subcelestial would be words like celestial, heavenly, extraterrestrial, or astral, which would describe things that are above or outside of the earth's atmosphere. Celestial, meaning of or relating to the sky or the heavens. Heavenly, meaning of or relating to a divine realm or the afterlife. Extraterrestrial, meaning of or relating to things outside the earth's atmosphere or beyond the solar system. Astral, meaning of or relating to the stars or heavenly bodies. These antonyms can broaden our understanding of different things above and below the earth's atmosphere.