Like a road going back to the continent (4)
I believe the answer is:
asia
'the continent' is the definition.
(Asia is an example)
'like a road going back' is the wordplay.
'like' becomes 'as'.
'a road' becomes 'AI' (resembles A1, a major UK road).
'going back' shows that the letters should be reversed in order.
'ai' back-to-front is 'ia'.
'as'+'ia'='ASIA'
'to' is the link.
(Other definitions for asia that I've seen before include "populous region" , "Part of the world" , "Tigers found here" , "lands in the east" , "A is A (anag)" .)