host and guest;  principal and auxiliary;  subject and object (philosophical);  subject and object
 immortal mountain wizard (in Taoism);  crane
 dying while traveling;  dying while abroad
 objectivity;  objective;  object (philosophical)
 passenger;  traveller;  traveler;  tourist
 guest of honor;  guest of honour;  good customer;  important customer
 unexpected (but welcome) visitor;  rare guest
 flood of customers;  roaring business
 guest of honor;  guest of honour;  main guest at a tea ceremony
 guest member;  associate member;  honorary member
 traveller (passing through);  traveler
 politician (or someone otherwise engaged in politics);  statesman
 foreign visitor;  foreign guest
 lone traveller;  lone traveler
 celestial body seen only for a short time (e.g. comet)
 land which one visits;  alien land;  topsoil brought from another place to mix with the soil
 man of letters;  man of taste;  art connoisseur;  narcissus