to collect a large amount of something over a period of time by gradually adding more

The system has the ability to cumulate data over a number of years. 这个系统有能力长期收集积累数据。

They have cumulated debts of over $10 million. 他们的债务积累到了超过一千万美元。

to gradually increase by combining with other things over a period of time

These small delays can cumulate and become a problem. 这些小的延迟累积起来可能成为一个大问题。