To waken means to wake up or to cause someone (or something) to wake up. When your alarm clock wakens you in the morning, it pulls you out of sleep. When a parent gently wakens a child for school, they're helping them transition from sleeping to being awake.

The word works in both directions: you can waken yourself by setting an alarm, or something external can waken you, like a dog barking or sunlight streaming through your window. A loud thunderclap might waken an entire household at once.

Waken appears often in stories and poetry, giving a slightly more formal or old-fashioned feeling than plain “wake up.” In The Secret Garden, when Mary discovers the hidden garden, the book describes how she helps waken it from its long neglect, bringing it back to life. This hints at another use: things besides people can waken. Spring wakens the world after winter's sleep. A great book might waken your curiosity about history.

The related word awaken means essentially the same thing, though awaken sometimes carries a stronger sense of something stirring to life after being dormant for a long time. But in everyday use, waken and awaken are nearly interchangeable, both more literary than simply saying “wake up.”