Mercury
Quicksilver
noun, の adjective
This is a fun one. Water silver is mercury, which makes a lot of sense. Mercury is liquidy like water, but it is all silver like silver. So silver water isn't some new mineral water you can get for $4 at the store, it's mercury! Or quicksilver, if you prefer.
すいぎん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
海魚の体が大きいほど体内にたくさん水銀がたまっています。
The larger the oceanic fish, the more mercury in its body.
水星と水銀はえい語で共にマーキュリーと言いますが、これはぐう然でしょうか。
I wonder if it's a coincidence that we call both Mercury, the planet, and mercury, the substance, "mercury" in English.
昔はみんな水銀体温計をお尻に差し込んでいたんだよね。めっちゃうける。
It’s so funny that people used to insert mercury thermometers into their butts.