'slip road' definitions:

Definition of 'slip road'

(from WordNet)
noun
A short road giving access to an expressway; "in Britain they call an access road a slip road" [syn: access road, slip road]

Definition of 'slip road'

From: GCIDE
  • 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]