One's taken in by fancy titles, interested only in top people (7)
I believe the answer is:
elitist
'interested only in top people' is the definition.
(interested only in the elites)
'one's taken in by fancy titles' is the wordplay.
'one' becomes 'I' (Roman numeral).
'taken in by' means one lot of letters goes inside another.
'fancy' indicates an anagram.
'titles' with letters rearranged gives 'eltist'.
'i' inserted inside 'eltist' is 'ELITIST'.
(Other definitions for elitist that I've seen before include "arrogant" , "for the cream" , "choosing the best" , "Favouring a select group" , "Favouring high society" .)