Ace reconstructed entire English racecourse (7)
I believe the answer is:
aintree
'english racecourse' is the definition.
'Aintree' can be an answer for 'racecourse' (horseracing venue in Liverpool). I am not certain of the 'english' bit.
'ace reconstructed entire' is the wordplay.
'ace' becomes 'a' (abbreviation).
'reconstructed' is an anagram indicator.
'entire' is an anagram of 'intree'.
'a'+'intree'='AINTREE'
Can you help me to learn more?
(Other definitions for aintree that I've seen before include "National racecourse" , "place for horse racing" , "6 National course" , "Home of the Grand National" , "Liverpool's racecourse" .)