Mount used by an academician in art (6)
I believe the answer is:
ararat
'mount' is the definition.
(I've seen this before)
'by an academician in art' is the wordplay.
'by' is a charade indicator (letters next to each other).
'an' becomes 'a'.
'academician' becomes 'RA' (member of the Royal Academy of Arts).
'in' means one lot of letters goes inside another.
'a' put next to 'ra' is 'ara'.
'ara' placed into 'art' is 'ARARAT'.
'used' acts as a link.
(Other definitions for ararat that I've seen before include "historic landing site" , "OT mount" , "Volcanic mount in eastern Turkey" , "Mount on which Noah's Ark is said to have landed" , "Biblical mountains" .)