Pompous sort (3)
'pompous sort' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ass that I've seen before include "Pompous fool or beast of burden" , "Foolish person; animal" , "Stupid person or American bum" , "slow-witted person" , "Dipstick" .)
(Other definitions for snob that I've seen before include "One attaching importance to social position" , "One for whom social status matters" , "He thinks that he is socially superior to others" , "Person with pretensions to higher social status" , "who puts on airs" .)