The word "most nonparticipating" indicates an individual or group that is largely uninvolved or apathetic towards a particular event or situation. Some antonyms for this term might include "highly engaged," "actively involved," "enthusiastic," "participatory," or "invested." These terms describe individuals who are highly committed to a cause or organization, willing to contribute their time, resources, and expertise. They are passionate about making a difference and taking action towards achieving their goals. In contrast to "most nonparticipating," these antonyms suggest a proactive and enthusiastic approach to involvement, indicating a desire to be fully engaged and dedicated to a particular initiative or project.