base layer; substratum; binder course
Technical term used in geology, construction, and linguistics for a foundational layer or underlying stratum.
Asphalt is used for the base layer of the road.
The substratum of this region is made of old bedrock.
substratum; substrate
fundamental culture; deep culture
Compound of 基 (ki, 'base, foundation') and 層 (sō, 'layer, stratum'). The exact historical derivation is uncertain, but the word follows standard Sino-Japanese compounding patterns.