Drama not unknown to philosopher (5)
I believe the answer is:
plato
'to philosopher' is the definition.
(Plato is an example)
'drama not unknown' is the wordplay.
I cannot really understand how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is present in the answer.
The remaining letters 'plat' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for plato that I've seen before include "Greek character" , "Moon crater named after Greek philosopher" , "Republic author" , "Greek philosopher (The Republic)" , "Teacher of Aristotle, pupil of Socrates" .)