Definitions

1. verb

to remove the elements of something (such as a pile of objects) so that they are no longer standing on top of one another

“She carefully began to unstack the boxes from the top shelf.”

2. verb

to take something apart from a pile or stack

“He unstacked the firewood for the winter season.”

3. noun

the act of removing the elements of something so that they are no longer standing on top of one another

“The process of unstacking the boxes took a few hours.”

4. noun

a pile or stack of something that is being or has been unstacked

“The unstack of boxes was a mess on the floor.”