Trivial insolence; quaint variety (15)
I believe the answer is:
inconsequential
'trivial' is the definition.
(I've seen this in another clue)
'insolence quaint variety' is the wordplay.
'variety' indicates an anagram.
'insolence'+'quaint'='insolencequaint'
'insolencequaint' anagrammed gives 'INCONSEQUENTIAL'.
(Other definitions for inconsequential that I've seen before include "Petty" , "unrelated to the foregoing" , "Trivial" .)