Eager artist joins band (6)
I believe the answer is:
raring
'eager' is the definition.
(similar in meaning)
'artist joins band' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'joins' means one lot of letters go next to another.
'band' becomes 'ring' (a ring is a band of metal).
'ra'+'ring'='RARING'
(Other definitions for raring that I've seen before include "Very eager (to do something)" , "Agog" , "Eager, impatient" , "Eager (to go?)" , "Very keen (to go?)" .)