Sat on top of is an expression which means to be situated or positioned above something. The antonyms for this phrase are to be situated or positioned below something, beneath or underneath. Other antonyms for this phrase may include inside, within, among, amidst, or surrounded by. These antonyms help to convey a sense of place or location, and can be used to describe the position of an object in relation to another. For example, one might say that the book was nestled within the pile of other books, rather than sitting on top of it. Using these antonyms can add variety and depth to your descriptions of position and location.