Rome: site designed for pedestrian (8)
I believe the answer is:
tiresome
'for pedestrian' is the definition.
(thesaurus)
'rome site designed' is the wordplay.
'designed' is an anagram indicator (designed with the letters).
'rome'+'site'='romesite'
'romesite' is an anagram of 'TIRESOME'.
(Other definitions for tiresome that I've seen before include "'Tedious, irksome (8)'" , "Fatiguing, tedious" , "Tedious, dull" , "Rather boring" , "irritating" .)