Large report from mogul (3,4)
I believe the answer is:
big shot
'mogul' is the definition.
(thesaurus)
'large report' is the wordplay.
'large' becomes 'big' (synonyms).
'report' becomes 'shot' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'big'+'shot'='BIG SHOT'
'from' is the link.
Can you help me to learn more?
(Other definitions for big shot that I've seen before include "Important influential person" , "VIP, informally" , "Important person (with a large cannon?)" , "Colloquially a very important person - quite noisy" , "somebody" .)