Crawl space and Subway

Crawl space noun - Low space beneath a floor of a building; gives workers access to wiring or plumbing.

Subway and crawl space are semantically related. in covered passageway topic. In some cases you can use "Subway" instead a noun phrase "Crawl space".

Subway noun - An electric railway operating below the surface of the ground (usually in a city).

Crawl space and subway are semantically related. You can use "Crawl space" instead a noun "Subway".