The adverb "mutinously" refers to a behavior characterized by rebellion or insubordination. Some possible synonyms for this word include defiantly, rebelliously, insubordinately, seditiously, unruly, and riotously. Other options might include mutinous, recalcitrant, or wayward, which can all convey a sense of resistance or opposition to authority. Ultimately, the choice of synonym will depend on the context and tone of the sentence, as well as the writer's specific intent and audience. Whether used to describe a political uprising or a disobedient child, the right synonym can help to convey the full depth and complexity of this difficult behavior.