__ up; accumulate

I believe the answer is:

pile

(Other definitions for pile that I've seen before include "A heap or stack" , "Arrange in stacks" , "large building" , "lot of money" , "Nap of a carpet" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.