Investigative, rather than snooty (4)
I believe the answer is:
nosy
'snooty' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I can't see?
I can't explain the rest of the clue.
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" .)