Nonfeasance is a term used to describe the failure of someone to perform an action that they have a legal obligation to do. Some of the antonyms for this word include compliance, performance, fulfillment, and execution. Compliance refers to the act of obeying or following rules, laws, or instructions. Performance, on the other hand, signifies the completion of a task or duty with efficiency and effectiveness. Fulfillment is the act of meeting one's obligations or responsibilities. Execution means performing an action or carrying out a plan effectively. These antonyms demonstrate the opposite of nonfeasance, emphasizing the importance of fulfilling obligations and responsibilities.