Poisonous : (of a substance or plant) causing or capable of causing death or illness if taken into the body.Foregone : past.Foreboding : a feeling that something bad will happen; fearful apprehension.Bad : of poor quality or a low standard.Ominous : giving the worrying impression that something bad is going to happen; threateningly inauspicious.Synonym of Ominous is Foreboding