Someone who relates swimming race to run (9)
I believe the answer is:
raconteur
'someone who relates' is the definition.
'raconteur' can be an answer for 'someone' (raconteur is a kind of someone). I am not sure about the rest of the definition.
'swimming race to run' is the wordplay.
'swimming' is an anagram indicator.
'race'+'to'+'run'='racetorun'
'racetorun' anagrammed gives 'RACONTEUR'.
Can you help me to learn more?
(Other definitions for raconteur that I've seen before include "source of stories?" , "A skilled storyteller, very entertaining" , "He tells a good story" , "Skilful teller of tales" , "A skilled story teller" .)