The term "most chapfallen" refers to a state of extreme sadness or humiliation. The opposite of this term could be "most exultant", meaning a feeling of extreme joy or triumph. Other antonyms for "most chapfallen" could include "most proud", "most confident", or "most self-assured". These words describe a state of being in which an individual feels happy, successful, and confident. While feeling chapfallen is a normal part of life, it is important to focus on the positive things in life and strive for feelings of exultation instead.