Poison
The kanji and the word are exactly the same. That means they share meanings as well.
どく
The reading for this word is the same as the kanji's reading.
働きすぎは体に毒ですよ。
Working too much is harmful to your body.
ビエトのつくえの引き出しには、コウイチをいつでも暗殺できるように毒の矢が仕こんである。
Viet is hiding a poison arrow in his desk drawer so that he can assassinate Koichi any time.
フグはとても美味しく、食べる人の心を豊かにしてくれますが、一方で猛毒も持っています。
While puffer fish is very delicious and provides a deeply satisfying culinary experience, it also carries a deadly poison.