Byway and Back street

Byway noun - A side road little traveled (as in the countryside).

Back street and byway are semantically related in road topic. In some cases you can use "Back street" instead a noun "Byway", when it comes to topics like path upon which travel occurs.

Back street noun - A narrow street with walls on both sides.

Byway and back street are semantically related in road topic. You can use "Byway" instead a noun phrase "Back street", if it concerns topics such as path upon which travel occurs.