Bedrock and Cobblestone

Bedrock noun - An immaterial thing upon which something else rests.

Cobblestone and bedrock are semantically related In some cases you can use "Cobblestone" instead a noun "Bedrock".

Cobblestone noun - Rectangular paving stone with curved top; once used to make roads.

Bedrock and cobblestone are semantically related in stone topic. Sometimes you can use "Bedrock" instead a noun "Cobblestone".