piled up like a mountain; a huge amount of something; a mountain of something, such as paperwork or bills

geological material that has accumulated or settled, such as sediment or a glacial kame

To play with or stack building blocks

hexagonal close-packed (HCP) structure in geometry or materials science

face-centered cubic packing, the most efficient way of packing spheres together in a crystal lattice

close-packing of spheres in mathematics or physics

A plain formed by the accumulation of silt, sand, and gravel over time, such as an alluvial plain or a coastal plain raised from the seabed.