Copper with upper-class person, isolated (3,3)
I believe the answer is:
cut off
'isolated' is the definition.
(thesaurus)
'copper with upper-class person' is the wordplay.
'copper' becomes 'cu' (chemical symbol).
'with' says to put letters next to each other.
'upper-class person' becomes 'toff' (I've seen this before).
'cu'+'toff'='CUT-OFF'
(Other definitions for cut off that I've seen before include "Sever, prevent from continuing" , "Leave nothing to in will - not a penny" , "Deadline" , "stop working" , "Device for interrupting a power supply" .)