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 subsidiary indication.
'english' becomes 'e' (abbreviation).
'composer' becomes 'arne' (I've seen this in other clues).
'in' is an insertion indicator.
'the outskirts of' suggests removing the centre.
'leatherhead' with its middle taken out is 'ld'.
'earne' placed 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".)