Soldiers really gutted by child (8)
I believe the answer is:
infantry
'soldiers' is the definition.
(I've seen this before)
'really gutted by child' is the wordplay.
'gutted' means to remove the middle letters (to gut something is to remove its insides).
'by' says to put letters next to each other.
'child' becomes 'infant' (infant is a kind of child).
'really' with its centre removed is 'ry'.
'ry' put after 'infant' is 'INFANTRY'.
(Other definitions for infantry that I've seen before include "Men fighting" , "Grunts" , "Army unit of foot soldiers" , "Unmounted fighters" , "Troops" .)