Most sunshiny can be described as something that is cheerful, bright, and optimistic. However, antonyms for this term would be gloomy, dreary, and pessimistic. If someone were to say that a day was not the most sunshiny, they might mean that it was dark, cloudy, or rainy. A person who is not very sunshiny might also be described as crabby, surly, or grumpy. It's important to remember that antonyms are useful for describing the opposite of a word, but they should be used sparingly and carefully to ensure that the intended meaning is accurately conveyed.