Intellectual in Clare gets real about brother (8)
I believe the answer is:
cerebral
'intellectual' is the definition.
('cerebral' can be a synonym of 'intellectual')
'clare gets real about brother' is the wordplay.
'clare' becomes 'ce' (I've seen this in other clues).
'gets' says to put letters next to each other.
'about' indicates putting letters inside.
'brother' becomes 'br'.
'real' going around 'br' is 'rebral'.
'ce'+'rebral'='CEREBRAL'
'in' acts as a link.
(Other definitions for cerebral that I've seen before include "Highly intellectual" , "Relating to the brain" , "Of the brain, intellectual" , "Concerning the brain" , "Intellectual, brainy" .)