Without stopping, negotiate Leeds, crossing north to south (7)
I believe the answer is:
endless
'without stopping' is the definition.
(never stopping or ending)
'negotiate leeds crossing north to south' is the wordplay.
'negotiate' is an anagram indicator (I've seen 'negotiated' mean this).
'crossing' is an insertion indicator.
'north' becomes 'N' (synonyms).
'to south' becomes 'S' (synonyms).
'leeds' is an anagram of 'edles'.
'edles' going around 'n' is 'endles'.
'endles'+'s'='ENDLESS'
(Other definitions for endless that I've seen before include "Tiresomely long" , "With no limit in sight" , "Sister of Aaron (Exodus)" , "Constant" , "Going on forever, lacking conclusion" .)