Rye, perhaps, welcomes British intellectual (8)
I believe the answer is:
cerebral
'intellectual' is the definition.
(I know that intellectual can be written as cerebral)
'rye perhaps welcomes british' is the wordplay.
'rye perhaps' becomes 'cereal' (rye is a kind of cereal).
'welcomes' indicates putting letters inside (in sense of 'invites in').
'british' becomes 'br' (abbreviation for British).
'cereal' enclosing 'br' is 'CEREBRAL'.
(Other definitions for cerebral that I've seen before include "Highly intellectual" , "Of the brain, intellectual" , "Relating to the brain" , "Intellectual, brainy" , "Concerning the brain" .)