visitor

noun

1. Someone who visits someone else; someone staying as a guest.

   “He ventured to raise his eyes again, and found his supernatural visitor confronting him in an erect attitude, with its chain wound over and about its arm.”

   “"'Tis some visiter," I muttered, "tapping at my chamber door— / Only this, and nothing more."”

   “There were many wooden chairs for the bulk of his visitors, and two wicker armchairs with red cloth cushions for superior people. From the packing-cases had emerged some Indian clubs,[…], and all these articles[…] made a scattered and untidy decoration that Mrs. Clough assiduously dusted and greatly cherished.”

   “The Riley Packaging plant in Uganda is quite a sight. From wall to wall and floor to ceiling, it is crammed with vast rolls of paper. A visitor feels like an ant gazing at stacks of toilet rolls.”

2. Someone who pays a visit to a specific place or event; a sightseer or tourist.

   “Warwick observed, as they passed through the respectable quarter, that few people who met the girl greeted her, and that some others whom she passed at gates or doorways gave her no sign of recognition; from which he inferred that she was possibly a visitor in the town and not well acquainted.”

   “Belgrade knew how to show visitors a good time, thanks to its fashionable, somewhat raucous nightclub and bar scene.”

3. (plural-normally)Someone, or a team, that is playing away from home.

   “But, somewhat against the run of play, Craddock fired the visitors ahead, volleying a low effort beyond Simon Mignolet after Sunderland twice failed to clear attempted crosses from Stephen Hunt.”

4. A person authorized to visit an institution to see that it is being managed properly.

   “As to eleemoſynary corporations, by the dotation the founder and his heirs are of common right the legal viſitors, to ſee that that property is rightly employed, which would otherwiſe have deſcended to the viſitor himſelf: […]”

5. (specifically)An extraterrestrial being on Earth.

   “5: Of course there is always the remote (I hope) possibility that instant panic will prompt us to send a hailstorm of nuclear warheads out upon the visitor.”

   “When we ask what evidence does in fact exist of extraterrestrial sojourns on our planet, we can start with what would surely be the best evidence of all: an actual visitor, or group of visitors, visible to crowds of people and ready for photo opportunities, television interviews, handshakes, polite conversation, and dancing.”

   “The visitor in Man Facing South-east claims pure altruism; Rantes (Hugo Soto) wants to alleviate the suffering of the poor and helpless.”

   “The tower radioed the flight leader, Captain Thomas F. Mantell, Jr., and requested that he engage and attempt to identify the strange visitor.”

6. An object which lands or passes by Earth or its orbit.

   “Within a few months, another small meteoric mass has been added to the list of those extra-terrestrial bodies which have fallen within the limits of Tennessee. This recent visitor is a stone, weighing, when first obtained, three pounds.”

   “This satellite, they suspect, is a visitor sent by the “superior beings” of a community of other stars within our Milky Way galaxy.”

   “Though Clube and Napier’s cometary visitor was not a planet, the story is surprisingly close to that of Worlds in Collision.”

7. (British)A head or overseer of an institution such as a college (in which case, equivalent to the university's chancellor) or cathedral or hospital, who resolves disputes, gives ceremonial speeches, etc.
8. The object in the visitor pattern that performs an operation on the elements of a structure one by one.