The Oxford Thesaurus An A-Z Dictionary of Synonyms - undesirablen.

1) persona non grata, pariah, outcast, exile, reject, leper: The police had many requests to run the undesirables out of town. --adj. 2) unwanted, objectionable, offensive, unacceptable, obnoxious, unsavoury, unwelcome, disliked, distasteful, repugnant, unfit, unbecoming, unsuitable: The parks are filled with tramps, drug addicts, and other undesirable elements.