The phrase "piles up" means to accumulate or gather things in large amounts. However, there are several antonyms for "piles up" that describe the opposite action. Some words that have opposite meanings to "piles up" include disperses, scatters, distributes, and spreads. Dispersing means to break something apart and scatter in various directions, while scattering means to throw something in different directions. On the other hand, distributing means to divide something and disperse it equally, while spreading means to expand its reach. Overall, these antonyms are useful in describing actions that are opposite to "piles up.