Tom Shore has become more refined (8)
I believe the answer is:
smoother
'more refined' is the definition.
Both the answer and definition are comparative adjectives. Perhaps there's an association between them I don't understand?
'tom shore has' is the wordplay.
'tom shore' can be anagrammed to 'SMOOTHER'.
Though, I'm unsure how this is indicated.
'become' is the link.
Can you help me to learn more?
(Other definitions for smoother that I've seen before include "Possibly an iron" , "More even" , "experiencing less turbulence" , "Flatter" , "(Of liquid) less lumpy" .)