society > travel > means of travel > route or way > other means of passage or access > [verb (transitive)] > supply with underground passages (2)
transitive. To dig or burrow in (the earth); to make a hollow, groove, or tunnel in; to fill with cavities or tunnels (frequently in passive). Also…
transitive. To provide (a street, city, etc.) with a subway (originally in sense 1, later usually in sense 2). Now rare.