"Old dock" refers to a place on a body of water where boats used to dock in the past but is no longer in use or has been there for a long time. Full definition
HP's old dock connector (so customers with the desktop dock purchased for older laptops won't have to trash them, though HP would prefer they eventually upgrade to a more capable Thunderbolt 3 dock) (windowscentral.com)
It super cute because it has a lot of old docks on it. (upbeatsoles.com)
The scene changes over time, starting out with underground raves in abandoned warehouses or old docked submarines, and morphing into parties at gigantic nightclubs with a velvet - rope policy at the door. (rogerebert.com)