Automobiles (4)
I believe the answer is:
cars
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">automobiles</span>' is the definition.<br/ ><span class="explanation-format__explanation">('car' can be a synonym of 'automobile')</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for cars that I've seen before include "Motor vehicles" , "... when these may be driven?" , "Private vehicles" , "Automobiles" .)