If you describe something as poisonous, you mean that it is extremely unpleasant and likely to spoil or destroy a good relationship or situation.
双语例句
例： poisonous comments.
恶毒的评论。
例： lying awake half the night tormented by poisonous suspicions.
半个晚上躺着都不能入眠，被卑劣的猜疑所煎熬。