The word "most chagrined" implies a feeling of great disappointment or irritation. Some antonyms for this phrase could be "pleased," "satisfied," "content," "elated," or "joyful." If someone is not "most chagrined," they might simply be "okay," "indifferent," or "neutral." Other antonyms could include "calm," "relaxed," or "unconcerned." These words paint a picture of someone who is not overly affected by a negative outcome or is able to move on easily. Antonyms for "most chagrined" can be used to describe a wide range of emotions, from complete happiness to a complete lack of concern.