Investigative, rather than snooty (4)
I believe the answer is:
nosy
'snooty' is the definition.
Both the definition and answer are adjectives. Maybe there's an association between them I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for nosy that I've seen before include "Inclined to poke into other people's affairs" , "Inquisitive in nasal manner" , "Meddlesome" , "Showing too much curiosity about people's affairs" , "Over-inquisitive" .)