electric, power (AmE)
mains (BrE)
three-pin, two-pin
The iron is fitted with a three-pin plug.

jack (BrE)
I pushed the jack plug into the amp.

pull out, remove, take out
fit, wire (BrE)
be fitted with
change

adapter
socket (esp. BrE)
My room only has one plug socket.

bath (BrE), bathtub (AmE), sink

put in
pull, pull out
I got out of the bath and pulled out the plug. (BrE)
I got out of the bathtub and pulled the plug. (AmE)
They decided to pull the plug on the project (= cancel it). (figurative)

hole (usually plughole)