Snooty arse sanctimonious about "end of art" (9)
I believe the answer is:
bumptious
'snooty arse sanctimonious about end of art' is the definition.
I can't judge whether this defines the answer.
'snooty arse sanctimonious about end of art' is the wordplay.
'snooty arse' becomes 'bum' (synonyms. I am not sure about the 'snooty' bit.).
'sanctimonious' becomes 'pious' (similar in meaning).
'about' means one lot of letters goes inside another.
'end of' suggests the final letters.
The last letter of 'art' is 't'.
'pious' placed around 't' is 'ptious'.
'bum'+'ptious'='BUMPTIOUS'
Can you help me to learn more?
(Other definitions for bumptious that I've seen before include "Irritatingly self-assertive" , "pushy?" , "Offensively self-assertive" , "self-important" .)