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.
Very bad; lousy.
Intense; extreme in degree or extent.
Dreadful; causing terror, alarm and fear; awesome
Formidable, powerful.
Unpleasant; disagreeable.
In a terrible way; to a terrible extent; terribly; awfully.