A soldier eating blooming rodent! (6)
I believe the answer is:
agouti
'rodent' is the definition.
(agouti is a kind of rodent)
'a soldier eating blooming' is the wordplay.
'soldier' becomes 'GI' (term for US soldier).
'eating' is an insertion indicator.
'blooming' becomes 'out' (plants which have bloomed are 'out').
'gi' going around 'out' is 'gouti'.
'a'+'gouti'='AGOUTI'
(Other definitions for agouti that I've seen before include "Caribbean rodent" , "Large rodent" , "Long-legged rabbit-sized rodent on Central and South America" , "animal" , "S. American burrowing rodent" .)