Mean to grow old around girl (7)
I believe the answer is:
average
'mean' is the definition.
('average' can be a synonym of 'mean')
'grow old around girl' is the wordplay.
'grow old' becomes 'age' ('age' can be a synonym of 'grow old').
'around' means one lot of letters goes inside another.
'girl' becomes 'vera' (**).
'age' placed around 'vera' is 'AVERAGE'.
'to' acts as a link.
(Other definitions for average that I've seen before include "mean maybe" , "Run of the mill" , "nothing special" , "'Medium, middling (7)'" , "The statistical norm" .)