The antonyms for the term "celestial beings" could be terrestrial beings or earthly creatures. Celestial beings describe entities that are believed to be of heavenly or divine origin, possessing supernatural or godly qualities. Terrestrial beings, on the other hand, refer to living organisms that inhabit the Earth, such as animals or humans. These two concepts are opposite in nature, one describing a realm beyond human understanding, and the other representing the material world that we are familiar with. While celestial beings inspire awe and reverence, terrestrial beings are more grounded and tangible, and are often subject to scientific study and scrutiny.