bedrock

adjective

Solid rock exposed at the surface of the Earth or overlain by unconsolidated material, weathered rock, or soil.

Pronunciation: /ˈbɛd.ɹɒk/ / /ˈbɛdˌɹɑk/

Etymology: From bed (“a layer on top of which something else rests.”) + rock.

The solid rock found at some depth below the ground surface.
“The denudation of the land was upon a grand scale. All superficial accumulations were swept away, and the bedrock was exposed.”
“Listen! It's big. Only eight to twenty feet to bedrock. There won't be a claim that don't run to half a million.”
A basis or foundation.
“If culture is the bedrock of a society, then language is the cornerstone of culture.”
“Now, although like most young people, Godfrey was indolent and evasive of difficulties, fearful of facing troubles also, he had a bedrock of character.”
The bones.

Etymology: From bed (“a layer on top of which something else rests.”) + rock.

To establish on a solid foundation.
“Bedrocked in the formative race relations of the Heart of Dixie, the governor declined an invitation to the unveiling of artist Maya Lin's civil rights memorial in downtown Montgomery.”