Glossy finish to Wales on its emblem (5)
I believe the answer is:
sleek
'glossy' is the definition.
(synonyms)
'finish to wales on its emblem' is the wordplay.
I cannot really understand how this works, but
'emblem' could be 'leek' (I have seen 'Emblem of Wales' mean 'leek' so perhaps 'emblem' could also mean 'leek') and 'leek' is located in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for sleek that I've seen before include "(Of hair) smooth, glossy" , "Elegant, streamlined" , "With a smooth, gleaming surface" , "Velvety" , "Well groomed" .)