By certain means, silly Vera shows her years (8)
I believe the answer is:
averages
'her years' is the definition.
I can't judge whether this definition defines the answer.
'by certain means silly vera' is the wordplay.
'by' means one lot of letters go next to another.
'certain means' becomes 'ages' (I can't explain this - if you can you should believe this answer much more).
'silly' indicates anagramming the letters.
'vera' with letters rearranged gives 'aver'.
'ages' after 'aver' is 'AVERAGES'.
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for averages that I've seen before include "Middle values" , "Means" , "Data included in cricket statistics" , "Save rage (anag.)" , "that are of great concern to cricketers" .)