Underneath is a common word used to describe something situated or located below or at the bottom of something else. However, there are many other words that can be used as synonyms for underneath. Some of these synonyms include beneath, below, bottom, base, lower, lowermost, down, nether, subterranean, and bottommost. These words can help add variety and depth to your writing, and can be particularly useful when describing location or placement. It's important to remember that different synonyms for a word may have different connotations or shades of meaning, so it's a good idea to consult a thesaurus to find the word that best fits your intended meaning.