piled — past tense of pile; to place things one on top of another in a heap

a woman carefully places another book on top of an already tall stack beside her desk. She reaches up on her tiptoes to add the book to the growing tower. The books have been piled so high that the stack now reaches above her shoulder height. Each book sits neatly on top of the one below it, creating a precarious but organized tower. Her husband watches nervously from nearby, ready to catch any books that might fall. A cat sits on the floor looking up curiously at the impressive height of the stacked books. books being placed one on top of another in a tall heap