The term "nosedived" means a sudden and rapid decline or drop in performance, quality, or success, usually in a negative or unfavorable sense. Antonyms of "nosedived" could be words like improved, escalated, soared, progressed, flourished, skyrocketed, or flourished. These words suggest a positive or upward trend of development or growth, instead of a sudden and sharp decrease like in the case of nosedived. Some other antonyms could be advanced, expanded, expanded, prospered, developed, thrived, surged, or climbed, which all indicate a positive and stable journey of progress or success. Antonyms to nosedived, therefore, describe an opposite and preferable situation where things are going smoothly and improving consistently.