Like parking stop, which may be on the road (7)
I believe the answer is:
asphalt
'road' is the definition.
(I've seen this before)
'like parking stop' is the wordplay.
'like' becomes 'as'.
'parking' becomes 'p' (abbreviation on road signs).
'stop' becomes 'halt' (halt can mean to stop).
'as'+'p'+'halt'='ASPHALT'
'which may be on the' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for asphalt that I've seen before include "Mixture of tar and gravel used in road surfaces" , "Roofers use this" , "Material for covering roads" , "Road surface material" , "petroleum residue" .)