IPA: /ˈweɪkfəl.nəs/
KK: /ˈweɪkfəlnəs/
The condition of being awake and alert, not asleep.
After a long night of studying, her wakefulness was starting to fade.
Wakefulness → It is formed from "wake" (from Old English *wacan*, meaning to become awake or to arise) and "-fulness" (meaning the state of being full of). The word "wakefulness" refers to the state of being full of wake or being alert and not asleep.
Think of the state of being 'full of wake' — 'wake' means to be alert, and '-fulness' indicates a state. This helps you remember that wakefulness means being alert and not asleep.