A rubber nose will have one (6)
I believe the answer is:
bridge
'a rubber' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for bridge that I've seen before include "Bony upper part of nose; card game" , "pontoon, perhaps" , "A walkover" , "Structure spanning a divide" , "Captain's area on a ship" .)