'Crumbling gable' artist's symbolic subject (7)
I believe the answer is:
algebra
'symbolic subject' is the definition.
'algebra' can be an answer for 'subject' (algebra is a kind of subject). I'm unsure of the 'symbolic' bit.
'crumbling gable artist's' is the wordplay.
'crumbling' is an anagram indicator.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'gable' is an anagram of 'algeb'.
'algeb'+'ra'='ALGEBRA'
Can you help me to learn more?
(Other definitions for algebra that I've seen before include "Symbol-based mathematical calculation" , "Branch of maths - real bag (anag)" , "Symbolic maths" , "Branch of generalised arithmetic" , "system employing symbols" .)