Warden gets motorist a drink (11)
I believe the answer is:
screwdriver
'a drink' is the definition.
(screwdriver is a kind of drink)
'warden gets motorist' is the wordplay.
'warden' becomes 'screw' (I am not sure about this - if you are sure you should believe this answer much more).
'gets' is a charade indicator (letters next to each other).
'motorist' becomes 'driver' (I've seen this before).
'screw'+'driver'='SCREWDRIVER'
Can you help me to learn more?
(Other definitions for screwdriver that I've seen before include "it gives the fixer a turn" , "Cocktail (vodka and 4 down juice)" , "Hand tool - cocktail" , "that'll turn a few heads" , "Tool for turning fastening device" .)