Ebulliency refers to the quality of being exuberant or enthusiastic, and its antonyms are words that represent the opposite characteristics. Some antonyms for ebulliency include apathy, lethargy, dispassion, and indifference. These words suggest a lack of interest, excitement, or passion, and show a subdued or withdrawn demeanor. Other antonyms for ebulliency are depression, sadness, dejection, and gloom, which indicate a state of low mood or hopelessness. These opposite words to ebulliency are handy to use when someone is trying to tone down an excessively energetic or high-spirited person, or when trying to describe a dull or uninteresting situation.