In conclusion, silver jewellery on old woman shows veiny appearance (8)
I believe the answer is:
marbling
'veiny appearance' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'in conclusion silver jewellery on old woman' is the wordplay.
'in conclusion silver' becomes 'r' (I can't explain this - if you can you should believe this answer much more).
'jewellery' becomes 'bling' (informal term for jewellery).
'on' says to put letters next to each other.
'old woman' becomes 'ma' (both can mean someone's mother).
'r'+'bling'='rbling'
'rbling' put after 'ma' is 'MARBLING'.
'shows' is the link.
Can you help me to learn more?
(Other definitions for marbling that I've seen before include "Streaky lines" , "Distribution of fat" , "Mottled effect" .)