Top of hat lost in walkway (8)
I believe the answer is:
footpath
'walkway' is the definition.
(thesaurus)
'top of hat lost' is the wordplay.
'lost' indicates anagramming the letters.
'top'+'of'+'hat'='topofhat'
'topofhat' with letters rearranged gives 'FOOTPATH'.
'in' is the link.
(Other definitions for footpath that I've seen before include "Way for pedestrians beside road" , "Thoroughfare for pedestrians" , "Countryside right of way" , "cross-country route" , "Track for pedestrians" .)