Most of ointment, round used for discharge (5)
I believe the answer is:
salvo
'discharge' is the definition.
(thesaurus)
'most of ointment round' is the wordplay.
'most of' means to remove the last letter.
'ointment' becomes 'salve' ('salve' can be a synonym of 'ointment').
'round' becomes 'o' (round can mean a round object).
'salve' with its last letter taken away is 'salv'.
'salv'+'o'='SALVO'
'used for' acts as a link.
(Other definitions for salvo that I've seen before include "Simultaneous discharge of guns" , "Simultaneous burst of gunfire" , "Artillery salute" , "Simultaneous firing of weapons" , "Burst (of applause, insults, artillery etc)" .)