pile up
US /paɪl ʌp/
UK /paɪl ʌp/

1.
堆积, 积压
to accumulate or increase in quantity, especially to an unmanageable degree
:
•
The dirty dishes started to pile up in the sink.
脏盘子开始在水槽里堆积起来。
•
Work tends to pile up when you're on vacation.
度假时工作往往会堆积如山。