Spanned the greatest street, we hear (8)
I believe the answer is:
bestrode
'spanned' is the definition.
(I've seen this before)
'greatest street we hear' is the wordplay.
'greatest' becomes 'best' (similar in meaning).
'street' becomes 'road' (I've seen this in another clue).
'we hear' indicates a 'sounds like' (homophone) clue.
'road' sounds like 'rode'.
'best'+'rode'='BESTRODE'
'the' is the link.
(Other definitions for bestrode that I've seen before include "Stood astride or over" , "spanned" .)