The antonym of "most exulting" can be a word like "dejected," which means feeling sad or down. Another word that can serve as an antonym can be "disheartened," which refers to losing hope or enthusiasm. Some other opposites of "most exulting" may include words like "unhappy," "unfulfilled," and "dissatisfied," all of which have a negative connotation. On the other hand, antonyms like "restrained," "modest," and "quiet" can be used to convey a sense of humility or restraint in contrast to "most exulting," which means feeling great joy or pride. Regardless of the antonym used, it can convey a completely opposite meaning from the original word.