Intellectual elevated sibling and wife (8)
I believe the answer is:
highbrow
'intellectual' is the definition.
(I know that highbrow is a type of intellectual)
'elevated sibling and wife' is the wordplay.
'elevated' becomes 'high' (I've seen this in another clue).
'sibling' becomes 'bro' (I've seen this before).
'and' is a charade indicator (letters next to each other).
'wife' becomes 'w' (abbreviation).
'high'+'bro'+'w'='HIGHBROW'
(Other definitions for highbrow that I've seen before include "Intellectual with lofty forehead?" , "Intellectual - cultured" , "Highly cultured or educated" , "Person of erudite tastes" .)