He stood there with a book tucked under his arm, waiting for the bus.
Tips
usage
挟 literally means to tuck something under the arm, then figuratively to coerce by holding leverage. Common in 要挟 (to blackmail) and 裹挟 (to sweep along by force).
Right side 夹 (to clamp from both sides) supplies the sound (jiā drifting to xié) and reinforces the meaning of pressing something tightly under the arm.