A bend; turn; curve; curvature; a flexure.

“She held the baby in the crook of her arm.”

A bending of the knee; a genuflection.

A bent or curved part; a curving piece or portion (of anything).

“the crook of a cane”

To bend, or form into a hook.

“He crooked his finger toward me.”

To become bent or hooked.

To turn from the path of rectitude; to pervert; to misapply; to twist.