Meaning

• A recipient of hospitality, specifically someone staying by invitation at the house of another.

  "The guests were let in by the butler."

• A patron or customer in a hotel etc.

  "Guests must vacate their rooms by 10 o'clock on their day of departure."

• An invited visitor or performer to an institution or to a broadcast.

  "The guest for the broadcast was a leading footballer."

• A user given temporary access to a system despite not having an account of their own.

• Any insect that lives in the nest of another without compulsion and usually not as a parasite.

• An inquiline.

Meaning

• To appear as a guest, especially on a broadcast

• As a musician, to play as a guest, providing an instrument that a band/orchestra does not normally have in its line up (for instance, percussion in a string band)

• To receive or entertain hospitably.