The word "unearthly" typically refers to something that doesn't belong to the physical world, something supernatural or strange. As such, its antonyms tend to be words that describe or denote things related to the physical realm. Words like "terrestrial," "natural," or "earthy," convey this meaning. "Mundane," "ordinary" and "common" are also antonyms; they refer to things that are commonplace, regular or everyday. Words like "familiar," "conventional" or "routine" can also work as antonyms to "unearthly." Alternatively, words like "mundane," "earthly," and "ordinary" are used to describe something that is commonplace or lacks any kind of mystical or spiritual element.