(a.) Having the quality of tainting or vitiating; tending to produce corruption.

apocalyptic bad baneful bitchy black bodeful boding corroding corrosive corrupting corruptive counterproductive cussed damaging dark deadly deleterious detrimental dire direful disadvantageous disserviceable distressing doomful dreary evil evil-starred fateful foreboding gloomy harmful hateful hurtful ill ill-boding ill-fated ill-omened ill-starred inauspicious iniquitous injurious invidious lethal lowering malefic maleficent malevolent malicious malign malignant mean menacing mischievous nasty noisome noxious of evil portent ominous ornery pernicious poisonous portending portentous prejudicial scatheful sinister somber threatening toxic unfavorable unfortunate unlucky unpromising unpropitious untoward venenate veneniferous venenous venomous vicious virulent wicked