The most common and most likely answer to this crossword clue is the 6 letter word CALLER
I've seen this crossword clue in Financial Times
C
A
L
L
E
R
More clues leading to the result CALLER
- Visitor caught everyone with Queen
- One visiting Cherbourg initially has to go across the Channel
- Visitor found in the bingo hall
- Visitor making request for medical help in US?
- Guest for the bingo official
- Singer but not a soprano, leading lady, one normally greeted?
- Visitor's vehicle parked outside alley is stripped
- One visiting California, the French Republican
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CALLER mean?
CALLER noun- The person who makes a telephone call.
- A visitor.
- (bingo) The person who stands at the front of the hall and announces the numbers.
- A function that calls another (the callee).
- A whistle or similar item used to call foxes.
- The person who directs dancers in certain dances, such as American line dances and square dances.