The antonyms for the word "sleep-inducing" are quite broad as they encompass all those elements which induce wakefulness, alertness, and restlessness. These elements might include music with a fast beat, caffeine, intense physical activity, bright lights, stimulating conversations, exciting activities or events, and much more. Anything that triggers excitement or a sense of eagerness can work as an appropriate antonym to "sleep-inducing." Additionally, words like vibrant, exhilarating, and invigorating can also be considered as antonyms for "sleep-inducing." Overall, there are numerous ways to combat sleepiness and enhance wakefulness, and the possibilities are endless.