A rum is drunk, admits a warrior (7)
I believe the answer is:
samurai
'warrior' is the definition.
(I know that samurai is a type of warrior)
'a rum is drunk admits a' is the wordplay.
'drunk' is an anagram indicator.
'admits' means one lot of letters goes inside another (to admit is to allow in).
'a'+'rum'+'is'='arumis'
'arumis' is an anagram of 'samuri'.
'samuri' going around 'a' is 'SAMURAI'.
(Other definitions for samurai that I've seen before include "Japanese warrior code" , "military type" , "Seven -, film directed by Kurosawa" , "military man" , "Traditional Japanese warrior" .)