Publicising ruins gran visited (11)
I believe the answer is:
advertising
'publicising' is the definition.
(I've seen this before)
'ruins gran visited' is the wordplay.
'ruins' indicates anagramming the letters.
'gran'+'visited'='granvisited'
'granvisited' is an anagram of 'ADVERTISING'.
(Other definitions for advertising that I've seen before include "Public promotion" , "Commercial world?" , "Publicising" , "Publicity needed!" .)