Mean woman in maturity (7)
I believe the answer is:
average
'mean' is the definition.
('average' can be a synonym of 'mean')
'woman in maturity' is the wordplay.
'woman' becomes 'vera' (a woman's name**).
'in' means one lot of letters goes inside another.
'maturity' becomes 'age' (I've seen this before).
'vera' put inside 'age' is 'AVERAGE'.
(Other definitions for average that I've seen before include "nothing special" , "representative figure?" , "par" , "Normal amount" , "building society customer loses capital over time" .)