Doctor (single) is a bit of a bore (5)
I believe the answer is:
drone
'bit of a bore' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'doctor single' is the wordplay.
'doctor' becomes 'Dr' (abbreviation).
'single' becomes 'one' (a single thing - only one).
'dr'+'one'='DRONE'
'is a' acts as a link.
Can you help me to learn more?
(Other definitions for drone that I've seen before include "Male bee - monotonous hum" , "Continuous hum" , "Bertie Wooster, say" , "Buzzing sound" , "fine lady?" .)