Letter from Greece (old Antioch) bought and adapted for a play (4,3,5,7)
I believe the answer is:
much ado about nothing
'for a play' is the definition.
(I've seen this before)
'letter from greece old antioch bought and adapted' is the wordplay.
'letter from greece' becomes 'mu' (letter from the Greek alphabet).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'adapted' is an anagram indicator.
'o'+'antioch'+'bought'+'and'='oantiochboughtand'
'oantiochboughtand' with letters rearranged gives 'chadoaboutnothing'.
'mu'+'chadoaboutnothing'='MUCH ADO ABOUT NOTHING'
(Other definitions for much ado about nothing that I've seen before include "having significant dealings with love?" , "exaggerated fuss" , "Hero marries a man in this play" .)