Antonyms for the word "is overjoyed" can be various, depending on the context. Some of them may include: disappointed, sad, unhappy, dissatisfied, frustrated, gloomy, dejected, distressed, miserable, melancholy, despondent, downhearted, crestfallen, disheartened, dispirited, and somber. These words can express the opposite of the feeling of being extremely happy, ecstatic, or thrilled. For example, if someone was expecting to receive an award but did not get it, they may feel disappointed instead of overjoyed. Similarly, if someone faced a big loss or tragedy, they may feel sad and distressed instead of being overjoyed.