1. a foundation layer of material placed beneath a base course in road or pavement construction
Usage: engineering; construction
2. an underlying foundation or support structure
Usage: technical

Examples

• The engineers laid a gravel subbase before pouring the concrete.
• A proper subbase is essential for preventing road damage from frost.
• The subbase must be compacted to ensure stability.
• Workers spread crushed stone for the highway subbase.
• The building’s subbase was reinforced with steel mesh.
• Poor drainage in the subbase caused the pavement to crack.