The word upsurging refers to an increase or rise in something. As such, antonyms for the term would be words that convey a decrease or a decline in something. Some possible antonyms for upsurging include decreasing, falling, declining, plummeting, dwindling, weakening, subsiding, and diminishing. These words are opposite in meaning to upsurging as they signify a decline or drop in something. Other antonyms for upsurging could be exodus, slump, desist, or downswing. These words showcase a movement away from growth, improvement or progress. Overall, antonyms for upsurging reflect the opposite direction of upward motion and signify decline or a reduction in something.