So is on the spot with the van (9)
I believe the answer is:
therefore
'so' is the definition.
(I know that so can be written as therefore)
'on the spot with the van' is the wordplay.
'on the spot' becomes 'there' (I've seen this before).
'with' means one lot of letters go next to another.
'the van' becomes 'fore' (I can't justify this - if you can you should give a lot more credence to this answer).
'there'+'fore'='THEREFORE'
'is' acts as a link.
Can you help me to learn more?
(Other definitions for therefore that I've seen before include "In consequence" , "has a triangular formation in maths?" , "as result" , "Thus" , "Consequently - for that reason" .)