Means of transport briskly withdrawn (5)
I believe the answer is:
trams
'means' is the definition.
Although both the answer and definition are plural nouns, I don't see how they can define each other.
'transport briskly withdrawn' is the wordplay.
'transport' becomes 'tram' (method of transport).
'briskly withdrawn' becomes 's' (I can't justify this - if you can you should believe this answer much more).
'tram'+'s'='TRAMS'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for trams that I've seen before include "People movers" , "public transport" , "old vehicles" , "silk yarns" , "Not seen in London" .)