Across a thoroughfare, drive (7)
I believe the answer is:
astride
'across' is the definition.
(thesaurus)
'a thoroughfare drive' is the wordplay.
'thoroughfare' becomes 'st' (I can't justify this - if you can you should give a lot more credence to this answer).
'drive' becomes 'ride' ('ride' can be a synonym of 'drive').
'a'+'st'+'ride'='ASTRIDE'
Can you help me to learn more?
(Other definitions for astride that I've seen before include "Not side saddle" , "Passing across" , "With a leg on both sides" , "With legs on each side" , "With legs stretched apart - tirades (anag)" .)