Article changing 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 unsure of the 'english' bit.
'article changing entire' is the wordplay.
'article' becomes 'a' (the indefinite article in English).
'changing' indicates an anagram.
'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 "6 National course" , "Grand National course" , "Liverpool race course" , "Home of the Grand National" , "Merseyside racecourse" .)