It helps furnish a police inspector with transportation (5)
I believe the answer is:
divan
'it helps furnish a police' is the definition.
The definition suggests a singular noun which matches the answer.
'inspector with transportation' is the wordplay.
'inspector' becomes 'di' (abbreviation for Detective Inspector).
'with' says to put letters next to each other.
'transportation' becomes 'van' (I can't justify this - if you can you should give a lot more credence to this answer).
'di'+'van'='DIVAN'
Can you help me to learn more?
(Other definitions for divan that I've seen before include "Long backless sofa" , "Piece of furniture" , "Couch - bed" , "Sofa - bed" , "Viand (anag.)" .)