Erudite English composer in the outskirts of Leatherhead (7)
I believe the answer is:
Here is my best explanation:
'erudite' is the definition.
('learned' can be a synonym of 'erudite')
'english composer in the outskirts of leatherhead' is the wordplay.
'english' becomes 'e' (abbreviation).
'composer' becomes 'arne' (I've seen this before**).
'in the' is an insertion indicator.
'outskirts of' means to remove the middle letters.
'leatherhead' with its centre removed is 'ld'.
'earne' going into 'ld' is 'LEARNED'.
(Other definitions for learned that I've seen before include "Wise, educated", "Discovered, ascertained", "Gained knowledge", "Acquired and digested knowledge", "Picked up - well-read", "Well-educated", "Acquired information, being well educated", "Having great knowledge", "Was taught" and "Gained understanding".)