Rest fitfully on alien road (6)
I believe the answer is:
street
'road' is the definition.
(I know that road can be written as street)
'rest fitfully on alien' is the wordplay.
'fitfully' indicates an anagram (I've seen this in other clues).
'on' is a charade indicator (letters next to each other).
'alien' becomes 'et' (extra terrestrial).
'rest' anagrammed gives 'stre'.
'stre'+'et'='STREET'
(Other definitions for street that I've seen before include "Road lined with buildings" , "lane" , "Perry's Della" , "Way; setter (anag.)" , "Roadway" .)