1 also stack up [intransitive and transitive]
to make things into a neat pile, or to form a neat pile:
The assistants price the items and stack them on the shelves.
a stacking hi-fi system
2 [transitive usually passive]
to put neat piles of things on something:
He went back to stacking the shelves.
be stacked with something
The floor was stacked with boxes.
used to say that someone is unlikely to be successful
4 British English stack the deck American English informalDGC
to arrange cards dishonestly in a game
stack upphrasal verb
to make things into a neat pile
used to talk about how good something is compared with something else
stack up against
Parents want to know how their kids' schools stack up against others.
if a number of things stack up, they gradually collect or get stuck in one place:
Traffic stacked up behind the bus.