Bless its fancy flourishes (8)
I believe the answer is:
sanctify
'bless' is the definition.
(I know that bless can be written as sanctify)
'its fancy flourishes' is the wordplay.
'flourishes' indicates anagramming the letters (I've seen 'flourishing' mean this (letters grow or flourish differently)).
'its'+'fancy'='itsfancy'
'itsfancy' with letters rearranged gives 'SANCTIFY'.
(Other definitions for sanctify that I've seen before include "Bless" , "Make holy or sacred" , "Consecrate, render holy" .)