re ‧ cluse /rɪˈkluːs $ ˈrekluːs/ BrE AmE noun [countable]
[ Date: 1100-1200 ; Language: Old French ; Origin: reclus 'shut up' , from Late Latin recludere 'to shut up' ]
someone who chooses to live alone, and does not like seeing or talking to other people:
She became a recluse after her two sons were murdered.
—reclusive /rɪˈkluːsɪv/ adjective