Narcolepsy is a disorder that causes excessive sleepiness and an inability to stay awake during the day. Therefore, the antonyms for narcoleptic would be words that describe wakefulness, alertness, and energy. Some of the antonyms that can be used for narcoleptic are insomniac, energized, vigilant, active, awake, lively, and alert. All these words refer to being awake and alert, which is opposite to the symptoms of narcolepsy. Using these antonyms for narcoleptic will provide a clear understanding that the opposite of the disorder is to be awake and full of energy.