Infuriated by the grenade explosion (7)
I believe the answer is:
angered
'infuriated' is the definition.
(synonyms)
'the grenade explosion' is the wordplay.
'explosion' is an anagram indicator.
'grenade' is an anagram of 'ANGERED'.
'by' is the link.
(Other definitions for angered that I've seen before include "Enraged (anag)" , "En garde (anag.)" , "Very annoyed" , "In high dudgeon" , "Infuriated" .)