noun
- the bottom or lower surface of something
Examples
- The undersurface of the leaf was covered with tiny hairs.
- She examined the undersurface of the rock for fossils.
- The undersurface of the bridge needed repairs.
- Barnacles attached themselves to the undersurface of the boat.
- The undersurface of the table was rough and unfinished.
- Scientists studied the undersurface of the ice sheet.