Japanese language requires year on island (6)
I believe the answer is:
jersey
'island' is the definition.
(I've seen this before)
'japanese language requires year' is the wordplay.
'japanese' becomes 'j' (international code for Japanese vehicles).
'language' becomes 'erse' (Erse is an example).
'requires' means one lot of letters go next to another.
'year' becomes 'y'.
'j'+'erse'+'y'='JERSEY'
'on' acts as a link.
(Other definitions for jersey that I've seen before include "Garment - cow - island" , "Breed of cow; sweater" , "producer for farming programme?" , "Woolly" , "tax haven?" .)