Hilariousnesses is a funny and uncommon word used to describe things that are humorous or amusing. Some synonyms for hilariousnesses include comedy, wit, humor, funniness, amusement, and laughter. Each of these words describe a sense of light-heartedness and entertainment that may bring joy and laughter to those experiencing it. Some other words that could be used to replace hilariousnesses include jocularity, merriment, facetiousness, and drollery. Regardless of the word used, the idea conveyed is that of something that provides a sense of good humor, laughter, and entertainment.