Typical of girl kept in a long time (7)
I believe the answer is:
average
'typical' is the definition.
(thesaurus)
'girl kept in a long time' is the wordplay.
'girl' becomes 'vera' (**).
'kept in' means one lot of letters goes inside another.
'a long time' becomes 'age' ('age' can be a synonym of 'long time').
'vera' put inside 'age' is 'AVERAGE'.
'of' acts as a link.
(Other definitions for average that I've seen before include "Mean - medium" , "Run of the mill" , "'Medium, middling (7)'" , "Normal amount" , "Mean, median or middling" .)