Agency no longer in a slippery situation? (6)
I believe the answer is:
office
'agency' is the definition.
(I know that agency can be written as office)
I can't explain the remainder of the clue.
(Other definitions for office that I've seen before include "Subsidiary" , "Position of authority" , "Position in government?" , "Business room or religious rite" , "employment > service" .)