1. a neat pile of objects, typically one that is tall and narrow
2. a large amount of something
Usage: informal
3. a tall chimney or vertical exhaust pipe

1. to arrange objects in a neat pile
2. to fill or load with large quantities of something

Examples

• She placed the books in a neat stack on the desk.
• There’s a stack of papers waiting to be graded.
• The factory’s smoke stack towered above the building.
• Please stack the dishes carefully in the cupboard.
• They stacked the shelves with new merchandise.
• He has a stack of work to finish before Friday.
• The librarian asked students to stack the chairs after the meeting.