The antonyms for the word "more sleepyhead" are energetic, alert, wide-awake, lively, and awake. The term "more sleepyhead" suggests a person who has a tendency to sleep and be lazy, and is often used to describe someone who cannot wake up even after sufficient rest. These antonyms, on the other hand, represent the opposite of the term and describe people who are full of life, lively and alert. Using these antonyms in its place, one may describe someone as energetic and always ready to take on tasks or adventure. They complement and contrast the original term well, and can be useful for expanding one's vocabulary.