Do better than The Sun or upstage The Star? (8)
I believe the answer is:
outshine
'do better' is the definition.
'outshine' can be an answer for 'better' (thesaurus). I am unsure of the 'do' bit.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for outshine that I've seen before include "Do better than, being more brilliant" , "beat" , "Eclipse" , "Be much better than" , "Surpass in splendour like the sun" .)