Stuck-up one (4)
I believe the answer is:
snob
'stuck-up one' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for snob that I've seen before include "One attaching importance to social position" , "blackleg" , "He thinks that he is socially superior to others" , "Crispin" , "One who considers himself socially superior" .)