Court is after old money that's gone (7)
I believe the answer is:
extinct
'gone' is the definition.
(I've seen this before)
'court is after old money' is the wordplay.
'court' becomes 'ct'.
'is after' says to put letters next to each other.
'old' becomes 'ex'.
'money' becomes 'tin' (I've seen this before**).
'ex'+'tin'='extin'
'ct' after 'extin' is 'EXTINCT'.
'that's' acts as a link.
(Other definitions for extinct that I've seen before include "No more vital" , "No longer living, like dinosaur" , "No longer erupting" , "(Of a volcano) dead" , "No longer burning" .)