Most abating refers to something that is reducing or easing in intensity or severity. Antonyms for this word would include "increasing," "intensifying," "worsening," "amplifying," or "escalating." For instance, if the rainfall is most abating, it means that it's decreasing or easing off. But if it's increasing, intensifying, or escalating, we might expect an upcoming flood. Similarly, if a fever is most abating, it means that the body temperature is reducing. But if it's worsening or amplifying, it could lead to more severe symptoms. Thus, the antonyms of most abating highlight the opposite effects of reducing, easing, or calming down.