Possibly dies, alas, when attacked (8)
I believe the answer is:
assailed
'attacked' is the definition.
('assail' can be a synonym of 'attack')
'possibly dies alas' is the wordplay.
'possibly' is an anagram indicator.
'dies'+'alas'='diesalas'
'diesalas' is an anagram of 'ASSAILED'.
'when' acts as a link.
(Other definitions for assailed that I've seen before include "Violently attacked" , "Under attack" , "Went for" , "became aggressive" , "Set upon" .)