(a.) Causing detriment; injurious; hurtful.

adverse antagonistic bad baleful baneful conflicting contrary corroding corrosive corrupting corruptive counter counteractive counterproductive damaging deadly deleterious destructive difficult disadvantageous disserviceable distressing evil hard harmful hostile hurtful ill in opposition inimical injurious lethal malefic malevolent malign malignant mischievous miserable negative noisome not easy noxious ominous opposed opposing opposite pernicious poisonous prejudicial rigorous scatheful sinister stressful toxic troublesome troublous trying unadvantageous unfavorable unprofitable unrewarding untoward useless venenate veneniferous venenous venomous vicious virulent worthless wretched