Host's foe disembowelled in combat (5)
I believe the answer is:
wafer
'host's' is the definition.
(thesaurus)
'foe disembowelled in combat' is the wordplay.
'disembowelled' suggests removing the centre.
'in' indicates putting letters inside.
'combat' becomes 'war' (I've seen this in other clues).
'foe' with its centre taken out is 'fe'.
'fe' inserted inside 'war' is 'WAFER'.
(Other definitions for wafer that I've seen before include "Light thin biscuit" , "Thin type" , "A very thin plain biscuit" , "Piece of bread" , "Ice cream's biscuit" .)