形容詞 harmful:

1. injurious to physical or mental health
   同義詞：noxious
2. able or likely to do harm
3. causing or capable of causing harm
4. constituting a disadvantage
   同義詞：disadvantageous
5. contrary to your interests or welfare
   同義詞：adverse, inauspicious, untoward
6. tending to cause great harm
   同義詞：evil, injurious

1. Antitoxin is substance that acts against a poisonous substance and prevents it from having a harmful effect.
   抗毒素是抵抗有毒物質并防止其產生有害作用的物質。
2. Drunkenness is harmful to our health.
   醉酒對我們的身體有害。
3. Smoking is harmful to one's health.
   吸煙對健康有害。
4. It is generally accepted that smoking is harmful to our health.
   吸煙有害健康，這是大家公認的。
5. The new law was in a measure harmful.
   新的法律在某種程度上說是有害的
6. An injurious plant or animal, especially one harmful to human beings.
   有害動植物有害的植物或動物，尤指那些對人類有害的
7. It's harmful to your eyes to read in the bus.
   在公共汽車上看書對你的眼睛有害。
8. It is harmful to your health to drink too much.
   過量喝酒對你的身體有害。

harm.ful

adj.（形容詞）
Causing or capable of causing harm; injurious.
有害的：造成或能夠造成損害的；有害的

【引伸】
harm.fully
adv.（副詞）
harm.fulness
n.（名詞）