Approximate intersection (10)
I believe the answer is:
roundabout
'approximate intersection' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe there's a link between them I don't understand?
'approximate intersection' is the wordplay.
'approximate' becomes 'round' (I've seen this before).
'intersection' becomes 'about' (I can't justify this - if you can you should give a lot more credence to this answer).
'round'+'about'='ROUNDABOUT'
Can you help me to learn more?
(Other definitions for roundabout that I've seen before include "fun for children" , "A plaything" , "devious" , "Ride" , "playground attraction" .)