The antonyms for the phrase "most voluntarily" are words that refer to actions that are not willingly carried out. These words include "involuntarily," which means an action is done without the person's choice, "compulsively," meaning an action is done because of a compulsion or force, "unwillingly," which means the person is reluctant or hesitant to perform a task, and "coerced," which means an action is performed due to being forced or threatened. It is important to understand the opposite meanings of words, as it helps in using them effectively and accurately in written and spoken communication.