Consider returning fire with explosive device (7)
I believe the answer is:
examine
'consider' is the definition.
(thesaurus)
'returning fire with explosive device' is the wordplay.
'returning' is a reversal indicator.
'fire' becomes 'axe' (I've seen this before**).
'with' means one lot of letters go next to another.
'explosive device' becomes 'mine' (mine is a kind of explosive device).
'axe' reversed gives 'exa'.
'exa'+'mine'='EXAMINE'
(Other definitions for examine that I've seen before include "Inspect, peruse closely" , "Check" , "vet" , "Investigate" , "Inspect; question in court" .)