Piles and Tidy sum

Piles noun - A large number or amount.

Tidy sum is a synonym for piles. In some cases you can use "Tidy sum" instead a noun "Piles".

Tidy sum noun - (often followed by `of') a large number or amount or extent.

Piles is a synonym for tidy sum. Sometimes you can replace term "Piles" with "Tidy sum", this terms are similar.