Mean woman appearing in time (7)
I believe the answer is:
average
'mean' is the definition.
(I know that mean can be written as average)
'woman appearing in time' is the wordplay.
'woman' becomes 'vera' (a woman's name).
'appearing in' indicates putting letters inside.
'time' becomes 'age' (an age is a period of time).
'vera' going within 'age' is 'AVERAGE'.
(Other definitions for average that I've seen before include "nothing special" , "Mean - everyday" , "Normal in arithmetic way" , "Of no exceptional quality or ability" , "Middle value, the norm" .)