Urban area indicated by directions on a signpost (4)
I believe the answer is:
town
'urban' is the definition.
(thesaurus)
'area indicated by directions on a signpost' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'to' and 'to' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for town that I've seen before include "Built up area" , "Built-up area" , "Urban community" , "Borough" , "Won't be about population centre" .)