Speak for traitor held in empty office (5)
I believe the answer is:
orate
'speak' is the definition.
(orating is a kind of speaking)
'traitor held in empty office' is the wordplay.
'traitor' becomes 'rat' (I've seen this before).
'held in' is an insertion indicator.
'empty' means to remove the middle letters.
'office' with its middle removed is 'oe'.
'rat' put inside 'oe' is 'ORATE'.
'for' acts as a link.
(Other definitions for orate that I've seen before include "Make a formal speech" , "Talk pompously" , "Speak pompously and at length" , "Give speech" , "talk at length" .)