subfloor
nounUK /ˈsʌb.flɔː/
US /ˈsʌb.flɔːr/
The strong flat layer under the floor you walk on.
The builders laid the subfloor before putting down the wooden boards.
OTHER MEANINGS
2. The structural layer of boards or panels that supports the finished floor covering.
Plywood is often used as a subfloor in modern homes.
3. A layer beneath the visible surface in a vehicle or ship.
The mechanic checked the subfloor of the truck for rust.
4. Any supporting base beneath a main surface or platform.
The stage had a hidden subfloor to keep it level.