Department of Finance getting old lady evicted (6)
I believe the answer is:
office
'department' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
(Other definitions for office that I've seen before include "Professional or clerical duties are performed here" , "Position of authority" , "Administration room" , "Official position" , "Position, or building in which colours in layers" .)