Get away from Eastern mischief-maker, retreating (4)
I believe the answer is:
'get away' is the definition.
'eastern mischief-maker retreating' is the wordplay.
'eastern' becomes 'e'.
'mischief maker' becomes 'elf' (mischievous folk lore creature).
'retreating' is a reversal indicator.
'eelf' back-to-front is 'FLEE'.
'from' acts as a link.
(Other definitions for flee that I've seen before include "Do a runner" , "Run (from danger)" , "rush" , "Turn tail" , "Take to one's heels" .)