The antonyms for the word "un humorous" include terms like amusing, entertaining, funny, hilarious, and comical. These are all words that describe something that is lighthearted and has the potential to make people laugh or smile. Being unhumorous, on the other hand, means that something is dull, boring, or uninteresting. It lacks the ability to engage or entertain people, making it less appealing. The absence of a good sense of humor can make an individual or situation seem uptight or unpleasant. Therefore, it is important to cultivate humor and levity in life to ward off boredom and monotony.