Objectionable (9)
(Other definitions for repugnant that I've seen before include "Abhorrent" , "Loathsome" , "Very unwelcome" , "vile" , "Nasty" .)
'objectionable' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for undesirable that I've seen before include "bad news" , "Objectionable person" , "Not wanted" , "Not to be wished for" , "Not welcome" .)