The expression "nether side" refers to the lower or under parts of something, usually underground. There are several other terms that can be used to describe the same concept, such as "underworld," "inferno," "abyss," "deep," "subterranean," "bottom," "beneath," or "lowermost." These synonyms convey a sense of depth, darkness and mystery, often associated with the supernatural or the unknown. Depending on the context, the term "nether side" can be used to describe the underworld of mythology, the hidden depths of the sea or the dark corners of the human psyche. Exploring the various synonyms for this expression can add depth and nuance to any piece of writing.