I expect it's Devonport (Devon) as the next station west is offically Devonport Dockyard.
It's a long walk from Devonport (Devon) to Devonport Dockyard, well 5 minutes,
The Railway goes through Devonport tunnel, which has a former Railway house above (on Albert Road), and Devonport
GW▸ tunnel drains run into the former Southern Railway tunnel that crosses below.