Disreputable (but attractive) fliers and swimmers (7)
I believe the answer is:
'disreputable but attractive' is the definition.
(I've seen this before)
'fliers and swimmers' is the wordplay.
'fliers' becomes 'raf'.
'and' means one lot of letters go next to another.
'swimmers' becomes 'fish'.
(Other definitions for raffish that I've seen before include "Vulgarly flashy, disreputable" , "flashy and careless" , "Dashing" , "smart" , "Tawdry" .)