Bad in quality, awful, terrible.
Warning of bad consequences: ill-boding; portentous.
Expressing bad consequences: dreadful; dismal.
Requiring action to prevent bad consequences: urgent, pressing.
Tremendously bad.
Causing horror; terrible; shocking.
A person wearing a comic or grotesque costume in a parade of horribles.
A thing that causes horror; a terrifying thing, particularly a prospective bad consequence asserted as likely to result from an act.