The term "most ill-fitted" refers to something that is not suitable or appropriate for a particular purpose, occasion or situation. The antonyms for this phrase would be "well-suited", "appropriate", "fitting", "compatible", "suitable", "proper", "fit", "adequate", "befitting", and "congruous". These words all indicate a perfect match between the object or the idea and the environment or the context in which it is used. "Well-suited" implies a compatibility between two things or people, while "fitting" suggests that something is appropriate or suitable for the occasion. In conclusion, "most ill-fitted" can be replaced by many words that convey compatibility, appropriateness, and suitability.