Antonyms for the phrase "flare off" include calm down, suppress, extinguish, quell, and subdue. Flare off signifies sudden outbursts of emotion, energy, or fire, often resulting in a visible display of light and heat. Its antonyms, on the other hand, indicate the opposite state of being, where one's feelings, intensity, or flames become subdued, tempered down, or eradicated. By using appropriate antonyms, one can convey a different meaning or mood in a piece of writing or conversation. Therefore, it is essential to be aware of different antonyms to improve communication and language skills.