Drunk and asleep in walkway (9)
I believe the answer is:
esplanade
'walkway' is the definition.
(I know that esplanade is a type of Promenade)
'drunk and asleep' is the wordplay.
'drunk' indicates an anagram.
'and'+'asleep'='andasleep'
'andasleep' anagrammed gives 'ESPLANADE'.
'in' acts as a link.
(Other definitions for esplanade that I've seen before include "Seaside road" , "Seaside walking area" , "Level seashore walkway" , "front" , "Seafront walkway" .)