Pal shot on a motorway (5)
I believe the answer is:
amigo
'pal' is the definition.
(thesaurus)
'shot on a motorway' is the wordplay.
'shot' becomes 'go' (I've seen this in other clues**).
'on' is a charade indicator (letters next to each other).
'motorway' becomes 'mi' (resembles Mg, English motorway).
'a'+'mi'='ami'
'go' put after 'ami' is 'AMIGO'.
(Other definitions for amigo that I've seen before include "Pal from Madrid?" , "in a foreign land, my friend?" , "A Spanish pal" , "China (in Spain's view)" , "Friend in Spanish-speaking area" .)