Name just one vehicle (4)
I believe the answer is:
ivan
'name' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see a link between them that I can't see?
'one vehicle' is the wordplay.
'one' becomes 'i' (Roman numeral).
'vehicle' becomes 'van' (type of vehicle).
'i'+'van'='IVAN'
'just' acts as a link.
Can you help me to learn more?
(Other definitions for ivan that I've seen before include "in Russian history" , "Russian, say" , "First Russian tsar, 1547-84" , "Russian boy's name" , "'Terrible' emperor of Russia" .)