Artist with back trouble grabbing for one’s finery (7)
I believe the answer is:
regalia
'finery' is the definition.
(synonyms)
'artist with back trouble grabbing for one's' is the wordplay.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'with back trouble' becomes 'lia' (I can't justify this - if you can you should give a lot more credence to this answer).
'grabbing' means one lot of letters goes inside another.
'for one' becomes 'eg' (I've seen this in other clues).
'ra'+'lia'='ralia'
'ralia' going around 'eg' is 'REGALIA'.
Can you help me to learn more?
(Other definitions for regalia that I've seen before include "Insignia of royalty or office" , "Paraphernalia indicative of high office" , "Orb and sceptre, for example" , "Emblems of royalty used at coronations" , "Algeria (anag)" .)