Crossword Genius

Department of Finance getting old lady evicted (6)

Ross

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" .)

I've seen this clue in The Guardian.
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