Young chap in Vladivostok (3)
I believe the answer is:
lad
'young chap' is the definition.
(I've seen this before)
'in vladivostok' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LAD' can be found hidden inside 'vladivostok'.
(Other definitions for lad that I've seen before include "(Housman's Shropshire) boy" , "Scottish lover" , "A young chap into ballads" , "Youngster" , "Young fellow" .)