The phrase "big-ass" is often used to describe something that is excessively large or impressive in size. However, it is not always the most appropriate word choice. Some synonyms include immense, mammoth, colossal, gargantuan, and humongous. Other options might include titanic, behemoth, mountainous, jumbo, or towering. These alternatives can be used in a variety of contexts, such as describing an apartment that is "mammoth" in size, or a "colossal" burger at a restaurant. While "big-ass" may be a common term in casual conversation, using more specific and descriptive synonyms can help to add depth and variety to one's vocabulary.