The phrase "most ill-humored" is generally used to describe someone who is in a bad mood or is easily irritated. Antonyms for this word would include phrases such as "most cheerful", "most jovial", "most optimistic", "most upbeat" and "most easy-going". These words indicate a person who is generally happy and positive, and who is not easily upset or frustrated. Opposite to the term "most ill-humored", these antonyms all suggest a person who is approachable and friendly, making them a pleasure to be around. If you're looking to describe a person who has a positive and energetic demeanor, these antonyms would be useful to learn.