Wakeful means unable to sleep or being awake when you'd normally be sleeping. During a wakeful night, you lie in bed with your eyes open, your mind racing with thoughts, watching the ceiling or listening to every sound in the house. Maybe you're excited about tomorrow's field trip, or worried about a test, or just can't seem to turn your brain off.

The word also describes someone who stays alert and watchful on purpose. A wakeful guard keeps careful watch through the night, noticing every movement and sound. Parents often spend wakeful hours caring for a sick child, checking on them repeatedly instead of sleeping.

It's the opposite of sleepy or drowsy. When you have a wakeful period, time seems to crawl by. You might count sheep, read a book, or eventually drift off just before your alarm goes off. Being wakeful occasionally is normal, though too many wakeful nights can leave you exhausted and grumpy the next day.