The word prevising means to foresee, anticipate or plan for future events. However, there are several antonyms for the word prevising, which means having the opposite meaning. These antonyms include negligently, carelessly, haphazardly, unconsciously, accidentally, and unthinkingly. Negligently refers to performing a task without caring for it, while carelessly refers to doing something without any attention to detail or precision. Haphazardly refers to doing something in an unplanned or disorganized manner, while unconsciously refers to doing something without being aware of it. Accidentally refers to doing something by chance or unintentionally, while unthinkingly refers to doing something without using one's mind or intellect.