1. Smoking is a pernicious habit.
    抽烟是一种有害的习惯。

1. 有害无益的：permissive 宽容的;许可的 | pernicious 有害无益的 | pornographic 色情的

2. 恶性的：permutation test 排列检定 | pernicious 恶性的 | peroxidase method 过氧化物酶法

3.

3. 有害的,致命的：shrill 尖锐的 刺耳的 | pernicious 有害的 致命的 | propitious 吉利的

1. 有害的；恶性的
    If you describe something as pernicious, you mean that it is very harmful.

    e.g. I did what I could, but her mother''s influence was pernicious...
           我已尽力了，但是她母亲贻害颇深。
    e.g. There is a pernicious culture of excellence: everything has to be not merely good but the best.
           对于优秀存在着一种认识的误区：一切都务求最好。

1. working or spreading in a hidden and usually injurious way

    e.g. glaucoma is an insidious disease
           a subtle poison

    Synonym: insidioussubtle

2. exceedingly harmful

    Synonym: banefuldeadlypestilent