Femme fatale on the outskirts of San Sebastian getting to grips with hot temper (5)
I believe the answer is:
siren
'femme fatale' is the definition.
(I know that femme fatale can be written as siren)
'the outskirts of san sebastian getting to grips with hot temper' is the wordplay.
'the outskirts of san sebastian' becomes 'sn' (I am not sure about this - if you are sure you should believe this answer much more).
'getting to grips with' indicates putting letters inside.
'hot temper' becomes 'ire' (I've seen this before).
'sn' enclosing 'ire' is 'SIREN'.
'on' acts as a link.
Can you help me to learn more?
(Other definitions for siren that I've seen before include "Alarm; temptress" , "Temptress - warning device" , "Warning signal generator" , "Loud whistle or sea witch" , "Seductive woman" .)