Pass one's required to visit Virginia (4)
I believe the answer is:
visa
'pass' is the definition.
(pass allowing international travel)
'one's required to visit virginia' is the wordplay.
I cannot quite understand how this works, but
'one's' could be 'is' (Roman numeral) and 'is' is found in the answer.
'virginia' could be 'va' (US state abbreviation) and 'va' is found within the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for visa that I've seen before include "Stamp affixed to passport as permission to enter country" , "Endorsement allowing bearer to enter country" , "travel authority" , "Travel pass" , "ID" .)