毒草的英文：
noxious weed
poisonous plant
poisonous weeds

参考例句：

I destroy all noisome and rank weeds, I keep down all pestilent vapours
我摧毁了一切丛生的毒草，控制一切有害的烟雾。

They were as a few fragrant flowers amidst a dense accumulation of noxious weeds
她们就象大丛毒草中的几朵香花。

I destroy all noisome and rank weeds, I keep down all pestilent vapours.
我摧毁了一切丛生的毒草，控制一切有害的烟雾。

As a matter of fact, idealism, metaphysics and poisonous weeds are found in every country
事实上，无论哪个国家，都有唯心主义，都有形而上学，都有毒草。

To let the people have some idea of these poisonous weeds and noxious fumes so as to have them uprooted or dispelled
这是为了让人民见识这些毒草、毒气，以便锄掉它，灭掉它。

noxious是什么意思：
adj. 【文】有害的，有毒的

The noxious fumes that foul the air had been improved.
污染空气的毒烟已经被控制了。

Heavy industry pollutes our rivers with noxious chemicals.
重工业产生的有毒化学品会污染我们的河流。

To admit fresh air into(a mine, for example) to replace stale or noxious air.
使通风，使空气流通使新鲜空气进入（如矿井）以替换不新鲜的或有毒的空气

weed是什么意思：
n. 野草，杂草，烟草
v. 除草；铲除

Ill weeds grow apace.
野草长得快。

Weeds want no sowing
野草不必栽种

No garden without its weeds
没有不长草的园子

poisonous是什么意思：
adj. 有毒的；恶毒的

Lead poisoning( or plumbism )：Poisoning by accumulation of lead in the body.
铅中毒:铅在体内积累引起的中毒。

Suspicion is the poison of true friendship
猜疑伤害莫逆之交

The bottle is labeled poison.
瓶子上表明有毒。