Judge trading shilling for time in estate (6)

I believe the answer is:

assets

'estate' is the definition.
(thesaurus)

I don't understand the remainder of the clue.

(Other definitions for assets that I've seen before include "Useful or valuable possessions or qualities" , "Possessions and resources" , "Total value of possessions" , "Valuable property" , "Advantages" .)

I've seen this clue in The Guardian.

Want a hint initially instead of a full solution? Install my app