Outside water sports champion? (7)
I believe the answer is:
surface
'outside' is the definition.
(thesaurus)
'water sports champion?' is the wordplay.
'water sports' becomes 'surf' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'champion?' becomes 'ace' (both can mean a person excelling at something).
'surf'+'ace'='SURFACE'
Can you help me to learn more?
(Other definitions for surface that I've seen before include "Come up for air" , "Outer appearance" , "Worktop" , "Outside layer" , "Facade" .)