US subject accepts award for play (7)
I believe the answer is:
macbeth
'for play' is the definition.
(Shakespeare play)
'us subject accepts award' is the wordplay.
'us subject' becomes 'math' (US name for mathematics).
'accepts' is an insertion indicator.
'award' becomes 'CBE' (Commander of the Order of the British Empire award).
'math' enclosing 'cbe' is 'MACBETH'.
(Other definitions for macbeth that I've seen before include "In sleep murderer" , "from 6 & 12 VERDI & SHAKESPEARE] ?" , "Thane of 6" , "its name must not be mentioned" , "Ill-fated Shakespearean king" .)