Buffer created by E European monarch (8)
I believe the answer is:
polisher
'buffer' is the definition.
(someone who buffs or polishing)
'by e european monarch' is the wordplay.
'by' says to put letters next to each other.
'e european' becomes 'Polish' (Poland is in Europe).
'monarch' becomes 'ER' (abbreviation for Elizabeth Regina, British Queen).
'polish' next to 'er' is 'POLISHER'.
'created' acts as a link.
(Other definitions for polisher that I've seen before include "may be French" , "rubber" .)