This thing is no longer in circulation - much! (3)
I believe the answer is:
far
'much' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for far that I've seen before include "Remote" , "Distant" , "Very much" , "A long, long way to go" , "At a great distance way" .)