Tea given by empty officers' mess (5)
I believe the answer is:
chaos
'mess' is the definition.
(I've seen this before)
'tea given by empty officers'' is the wordplay.
'tea' becomes 'cha' (cha is a type of tea).
'given by' is a charade indicator (letters next to each other).
'empty' means to remove the middle letters.
'officers' with its middle removed is 'os'.
'cha'+'os'='CHAOS'
(Other definitions for chaos that I've seen before include "Total disorder and confusion" , "Bedlam" , "upheaval" , "disarray" , "Complete disorder and confusion" .)