The word "most energyless" refers to a state of extreme exhaustion or fatigue. Its antonyms include energetic, lively, active, vigorous, vivacious, sprightly, and lively. Energetic people are full of enthusiasm, energy, and willingness to work hard. Lively people are vibrant, enthusiastic, and full of life. Active individuals are dynamic, brisk, and lively, while vigorous folks are robust, energetic, and resilient. Vivacious individuals are lively, animated, and charismatic, and sprightly people are agile, nimble, and full of energy. In short, antonyms of "most energyless" describe individuals with a lively and robust outlook on life.