Special artist the Queen's elevated (4)
I believe the answer is:
rare
'special' is the definition.
(I've seen this before)
'artist the queen's elevated' is the wordplay.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'the queen' becomes 'er' (Elizabeth Regina).
'elevated' shows that the letters should be reversed in order.
'er' backwards is 're'.
'ra'+'re'='RARE'
(Other definitions for rare that I've seen before include "Very scarce like valuable antique" , "Ben Jonson was considered so" , "Very lightly cooked, meat say" , "Not common" , "Not easily come by like undercooked meat" .)