Bring up British swimmer (6)
I believe the answer is:
broach
'bring up' is the definition.
(I've seen this before)
'british swimmer' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC'**).
'swimmer' becomes 'roach' (roach is a kind of fish).
'b'+'roach'='BROACH'
(Other definitions for broach that I've seen before include "Bring up a topic" , "Raise (a subject) for discussion" , "Open (container, subject)" , "Start to speak" , "Raise (a sensitive subject)" .)