Quite mean to eclipse Republican (6)
I believe the answer is:
pretty
'quite' is the definition.
(synonyms)
'mean to eclipse republican' is the wordplay.
I cannot really see how this works, but
'republican' could be 'r' (abbreviation) and 'r' is located in the answer.
'mean' could be 'petty' (I've seen this in another clue) and 'petty' is located in the leftover letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for pretty that I've seen before include "Film with Julia Roberts (belle)" , "pulchritudinous" , "Somewhat - attractive" , "Facially attractive" , "Attractive, beautiful" .)