Umbilical connect port
The umbilical connect port was a connection port on a starship which was normally used while in spacedock during repairs or upgrades. An umbilical line at the station would connect with this port to perform whatever work needed to be done. 

The  encountered an automated repair station which used its ports as part of the repairs. ()

 starships also had these ports on the dorsal surface of the secondary hull. There was more than one of these ports on the 'spine' of the hull. The location of these ports was labeled on a schematic of the  that was seen on William T. Riker's bridge console. ()
Spacecraft components