1. adverb By very large degrees; rapidly or in quick progress forward. Our small company has been expanding leaps and bounds over the past year, thanks in no small part to our aggressive new marketing campaign. Our puppy has grown leaps and bounds since we switched it to a new brand of dog food.

2. noun Very large degrees of or rapid progress forward. (Used especially in the phrases "by/in leaps and bounds" and "make leaps and bounds.") Samantha's delivery business has been growing by leaps and bounds recently. The class made leaps and bounds in its reading comprehension after I adopted a new teaching method.