n.
  - a person who is invited to visit someone's home or attend a social or official function. 
▸a person invited to take part in a broadcast or entertainment.
 - a person staying at a hotel or boarding house.
 
v.
 appear as a guest in a broadcast or entertainment.
 
  Phrase
  
    - be my guest
 informal please do!  - guest of honour
 the most important guest at an occasion. 
   
  Etymology
  ME: from ON gestr, of Gmc origin.