A hairpin bend in seven reconstructed roads (7)
I believe the answer is:
avenues
'roads' is the definition.
(avenue is a kind of road)
'a hairpin bend in seven reconstructed' is the wordplay.
'hairpin bend' becomes 'u' (I can't justify this - if you can you should believe this answer much more).
'in' means one lot of letters goes inside another.
'reconstructed' is an anagram indicator.
'seven' is an anagram of 'venes'.
'u' going inside 'venes' is 'venues'.
'a'+'venues'='AVENUES'
Can you help me to learn more?
(Other definitions for avenues that I've seen before include "City streets or methods of approach" , "Tree-lined roads" , "Approaches" .)