Elitist initially seemed nervous over background (4)
I believe the answer is:
snob
'elitist' is the definition.
(thesaurus)
'initially seemed nervous over background' is the wordplay.
'initially' says to take the initial letters.
The first letters of 'seemed nervous over background' is 'SNOB'.
(Other definitions for snob that I've seen before include "blackleg" , "One has pretensions" , "Old cobbler" , "Prig" , "Elitist" .)