The concept of doing something on purpose implies a deliberate and intentional act. In contrast, antonyms for "done purpose" would suggest haphazard or unintentional behavior. Some opposing words to "done purpose" include accidental, spontaneous, inadvertent, unintended, and unplanned. These antonyms highlight a lack of foresight, planning, or intention, indicating that the act occurred without a specific goal or objective. While "done purpose" connotes responsibility and control, these antonyms suggest a lack of control or conscious decision-making. However, it's important to note that sometimes the opposite of "done purpose" may not necessarily mean negative or careless behavior.