The correct pinyin: duι. Pile means: pile up, pile up things with hands or tools, pile up things.
Explanation:
1, what accumulates together: stack. Stack houses. pile
2. Accumulate together, accumulate together: accumulate. Stack. Pile up the base. Piles. Pile it up.
3, quantifier, used for piles of things or a group of people: a bunch of people.
On the Idioms of Duxing Two-character and Four-character.
1, piling up mountains, nuclear reactors, piling up gold and jade, piling up silver and jade, piling up mountains, piling up jade, piling up red and green, drilling old paper piles, piling up residual cases, piling up mountains and seas, composting at high temperature, returning bags, piling up, piling up dead bodies, piling up cold soil, piling up mountains, selling goods, piling up mountains and laying bricks.
2. Paving, piling up, piling up sand, leaving, piling up, piling up snow, piling up, piling up firewood, piling up clouds, piling up graves, piling up yarn, piling up dragons, piling up bases, piling up red, piling up ice, piling up clusters, piling up culture, piling up materials, piling up lonely, piling up grain, piling up upside down, rolling up, piling up inside and piling up.