Dead on feet is an idiomatic expression that refers to extreme physical exhaustion or fatigue. Some antonyms for this term include energized, vibrant, lively, brisk, and refreshed. If you feel dead on your feet, you are far from being lively or energetic. You might feel drained, weak, or depleted. To counteract these feelings, you can try to engage in activities that are refreshing and invigorating. This might include taking a quick power nap, engaging in light exercise, or simply taking a break from work to meditate or relax. By doing things that help you recharge and renew your energy, you can avoid feeling dead on your feet and stay alert and focused throughout the day.