The word "fall-offs" refers to a decrease or decline in quantity, quality, or performance that occurs over time. Antonyms for this word would be "growth," "increase," or "improvement." These words describe a positive change in a particular area, such as a increase in sales or an improvement in academic performance. They suggest progress and development, rather than stagnation or decline. Other antonyms for "fall-offs" might include "success," "advancement," or "gains." Ultimately, the opposite of a fall-off is any kind of positive change or growth, and it can be characterized by a sense of forward momentum and improvement.