Prince is banished, retiring conclusively – hence King can relax (6)
I believe the answer is:
lounge
'relax' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lounge that I've seen before include "Idle man mixing with rich, fashionable people" , "Sit idly in comfortable room" , "Living room" , "Stand about idly - in posh bar?" , "Relax in sitting room?" .)