"Death Be Not Proud" poet (5)
I believe the answer is:
'death be not proud poet' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for donne that I've seen before include "John -, English poet" , "Writer of poetry" , "English preacher and metaphysical poet, d. 1631" , "basic assumption" .)