Demolish large new English comprehensive (7)
I believe the answer is:
general
'comprehensive' is the definition.
('general' can be similar in meaning to 'comprehensive')
'demolish large new english' is the wordplay.
'demolish' is an anagram indicator.
'new' becomes 'n'.
'english' becomes 'e' (abbreviation).
'large'+'n'+'e'='largene'
'largene' is an anagram of 'GENERAL'.
(Other definitions for general that I've seen before include "Non-specialist - army officer" , "Regular - officer" , "Usual; officer" , "Common - soldier" , "Enlarge for senior army officer" .)