When someone is not solemnly, they may appear to be more relaxed, casual, or even playful. Other synonyms to describe this state could be animated, lighthearted, cheerful, or jovial. Not taking things seriously can also suggest a sense of humor or even sassiness. Some other synonyms for not being solemn include carefree, buoyant, blithe, jaunty, or jocular. The use of antonyms like comical, humorous, witty, or amusing could also convey the same message. Whatever the word choice may be, not being solemnly suggests a bright and positive attitude.