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.
Remarkably bad; of poor quality.
Infested with lice.
Unwell; under the weather.
Dirty or untidy.
Underhanded; mean; contemptible.
Filled or packed (with something, usually bad).