By being a bit superior (3)
I believe the answer is:
per
'by' is the definition.
(thesaurus)
'a bit superior' is the wordplay.
'a bit' indicates the answer is hidden within the clue (the answer is formed by a bit of the clue).
'PER' is hidden within 'superior'.
'being' acts as a link.
(Other definitions for per that I've seen before include "Preposition indicating by means of" , "According to" , "Preposition meaning for each" , "For each or every" .)