Most bilious is an adjective that describes someone who is irritable, bad-tempered, and prone to angry outbursts. Antonyms for this word would be calm, composed, agreeable, and easygoing. A person who is described as most bilious is always in a grumpy mood, but someone who is calm and composed is always collected and in control of their emotions. An agreeable person is one who is easy to get along with and always willing to listen to others' opinions, while an easygoing person is one who is relaxed and flexible in their approach to life. Therefore, using antonyms for the word most bilious can help you understand and describe people who have entirely different personalities and attitudes.