Are you alert and restless at 4 am? Then you can say you're wakeful, or not able to sleep at all. You might as well get up and start your day.

If you're wide awake, especially when you should be asleep, you're wakeful. A wakeful baby can be perfectly pleasant in the middle of the day but is a lot less fun after midnight. Many new parents spend weeks or months of wakeful nights, and even getting a new puppy can lead to a long, wakeful period of your life. Before it meant simply "marked by being awake," this adjective meant "diligent."

Definitions of wakeful

adj marked by full consciousness or alertness

not in a state of sleep; completely conscious

adj carefully observant or attentive; on the lookout for possible danger

argus-eyed, open-eyed, vigilant
alert, watchful
engaged in or accustomed to close observation

adj (of sleep) easily disturbed

“a restless wakeful night”
not deep or strong; not affecting one deeply

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