Slip across the road (4)
I believe the answer is:
skid
This clue might be a double definition.
'slip across' is the first definition.
'skid' can be an answer for 'slip' (synonyms). I'm unsure of the 'across' bit.
'road' is the second definition.
(skid road is a kind of road)
'the' acts as a link.
Can you help me to learn more?
(Other definitions for skid that I've seen before include "Lose lateral control" , "What car may do on ice - be careful" , "Slide (on slippery ground)" , "Runner" , "Slip, slide" .)