The term "most plethoric" refers to being overly full or abundant. Its antonyms, therefore, would encompass words that describe a lack or deficiency in quantity. Examples of these opposites include words like scarce, sparse, depleted, meager, and scarce. Other antonyms for "most plethoric" could also include descriptors like deficient, insufficient, inadequate, and insufficient, all of which convey a sense of lacking or being incomplete. Whether used to describe physical objects, emotional experiences, or anything in between, the antonyms for "most plethoric" paint a contrasting picture of scarcity and shortage that end up enhancing the meaning of the original word.