corrugated sheet; corrugated plate
Refers to a sheet of material (metal, plastic, etc.) with a wavy cross-section, commonly used in roofing, siding, and packaging.
We laid corrugated sheets on the roof.
This corrugated sheet is made of plastic and is light.
Compound of 波 (nami, 'wave') and 板 (ita, 'board, sheet'), literally 'wave board', describing the wavy shape.