subgrade
/ˈsʌbɡreɪd/noun
1A subsidiary or subordinate grade; a secondary gradation; a grade within a grade.
2 Civil Engin. In the construction of roads and other flat load-bearing surfaces: the layer (typically the prepared natural ground) lying immediately beneath the foundations.
Origin
Late 18th century. From sub- + grade.
- somebody
- some day
- someday
- some few
- some hope
- somehow
- some little
- some more
- someone
- someone (or something or somehow etc.) or other
- someone's bark is worse than their bite
- someone's better nature
- someone's blood is worth bottling
- someone's ears are flapping
- someone's face fits
- someone's kind
- someone's name is mud
- someone's number is up
- someone's (or something's) days are numbered
- someone's (or the) best plan
- someone's tongue is hanging out
- someplace
- somersault
- Somerset
- Somerville