Pile up and Stacking up

Pile up verb - Arrange into piles or stacks.

Stacking up and pile up are semantically related In some cases you can use "Stacking up" instead a verb "Pile up".

Pile up and stacking up are semantically related in increase topic. Sometimes you can use "Pile up" instead a verb "Stacking up", if it concerns topics such as add up, gather or amass something, come or bring together.