Novel learning covering English mostly (2,7)
I believe the answer is:
in general
'mostly' is the definition.
(thesaurus)
'novel learning covering english' is the wordplay.
'novel' is an anagram indicator.
'covering' is an insertion indicator.
'english' becomes 'e' (abbreviation).
'learning' is an anagram of 'ingenral'.
'ingenral' going around 'e' is 'IN GENERAL'.
(Other definitions for in general that I've seen before include "by and large" , "Usually; mainly" , "on the whole" , "Commonly" , "Overall" .)