Chief butler in rank bad mood (5-4)
I believe the answer is:
major-domo
'chief butler' is the definition.
(major-domo can mean the head of a domestic staff)
'rank bad mood' is the wordplay.
'rank' becomes 'major' (military rank).
'bad' indicates anagramming the letters.
'mood' anagrammed gives 'domo'.
'major'+'domo'='MAJOR-DOMO'
'in' acts as a link.
(Other definitions for major-domo that I've seen before include "Household official" , "General steward" , "Chief steward or butler of a household" , "Chief steward of a great household" .)