[1] : The Collaborative International Dictionary of English v.0.48

slip road \slip road\ n.
   a short road giving access to an expressway british "in
   england they call an access road a slip road."

   syn: access road, slip road.
        wordnet 1.5

[2] : WordNet (r) 2.0

slip road
     n : a short road giving access to an expressway; "in england
         they call an access road a slip road" syn: access road
see also:
access road 

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