The word "assurgent" is an adjective that describes something or someone that is rising, ascending, or climbing. Its antonyms would be words that describe the opposite of this motion. Some of the antonyms for "assurgent" could include: descending, falling, dropping, sinking, declining, or lowering. These words all convey a sense of movement in the opposite direction of "assurgent." For instance, a person who is descending a mountain would be the opposite of one who is assurgent. Similarly, a stock price might be described as falling, or declining, rather than rising or assurgent.