Old coin found in early English school (7)
I believe the answer is:
educate
'school' is the definition.
('educate' can be a synonym of 'school')
'old coin found in early english' is the wordplay.
'old coin' becomes 'ducat' (I've seen this before).
'found in' means one lot of letters goes inside another.
'early english' becomes 'ee' (architectural abbreviation).
'ducat' going inside 'ee' is 'EDUCATE'.
(Other definitions for educate that I've seen before include "Enlighten" , "Teach - instruct" , "Give instruction to" , "Impart learning" , "what teacher should do, to be effective" .)