pile up pile up /paɪl ʌp/

verb

1. () Collect or gather  ( conglomerate , cumulate , amass , accumulate , gather , pile up )
   collect or gather
    Journals are accumulating in my office
   Journals are accumulating in my office
    The work keeps piling up
   The work keeps piling up
   
2. () Arrange into piles or stacks  ( heap up , stack up , pile up )
   arrange into piles or stacks
    She piled up her books in my living room
   She piled up her books in my living room
   
3. Get or gather together (a large number of something)  ( amass , hoard , pile up , accumulate , collect , compile , roll up )
   Get or gather together (a large number of something)
    I am accumulating evidence for the man's unfaithfulness to his wife
   I am accumulating evidence for the man's unfaithfulness to his wife
    She is amassing a lot of data for her thesis
   She is amassing a lot of data for her thesis
    She rolled up a small fortune
   She rolled up a small fortune