Female spy taking in new peer (8)
I believe the answer is:
viscount
'peer' is the definition.
(viscount is a kind of peer)
'female spy taking in new' is the wordplay.
'female' becomes 'vi' (short for Violet, a woman's name).
'spy' becomes 'scout'.
'taking in' means one lot of letters goes inside another.
'new' becomes 'n'.
'scout' going around 'n' is 'scount'.
'vi'+'scount'='VISCOUNT'
(Other definitions for viscount that I've seen before include "Nobleman" , "British noble" , "Minor peer" , "British peer" , "Lord" .)