The phrase "tailed off" denotes a decrease in intensity, volume, or speed. Its antonyms are words that convey the opposite meaning: increase, intensify, revive, or accelerate. For instance, words like escalate, surge, spike, soar, and boom are antonyms of tailed off when used in reference to speed or volume. Conversely, for intensity, antonyms include amplify, enhance, magnify, or fortify. Therefore, the use of antonyms can make writing more precise and help readers understand the intended context better. In conclusion, antonyms play a vital role in the English language, and using them correctly can add more dynamism and variety to your writing.