Showing an arrogant lack of respect (8)
I believe the answer is:
insolent
'showing an arrogant lack of respect' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for insolent that I've seen before include "Rude, showing lack of respect" , "Lippy" , "Impudent and disrespectful" , "Rude and disrespectful" , "Rudely disrespectful" .)