Peace keeper fellow packs uniform and ointment (7)
I believe the answer is:
unguent
'ointment' is the definition.
(I know that ointment can be written as unguent)
'peace keeper fellow packs uniform' is the wordplay.
'peace keeper' becomes 'un'.
'fellow' becomes 'gent' (synonyms).
'packs' means one lot of letters goes inside another (inserted letters are packed inside).
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'gent' enclosing 'u' is 'guent'.
'un'+'guent'='UNGUENT'
'and' acts as a link.
(Other definitions for unguent that I've seen before include "An ointment or lubricant" , "Ointment, soothing salve" , "Greasy ointment" , "Lubricant to tune gun" , "application" .)