Essential
Important, Necessary
noun, な adjective
When something has a heavy need, you know that that thing is essential. It is important.
じゅうよう
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.
重要なしょるいなので、なくさないよう注意してください。
They’re important documents, so please be careful not to lose them.
この国にとって、国民一人当たり一羽の白鳥をかうことはとても重要なことなんです。
For this country, it is very important that each citizen raises one swan.
私にとって人生で一番重要なものはビールですって？そんなこと言ってないわよ。言いもしないことを言ったなんて言わないでよ。
The most important thing in my life is beer? I didn’t say that! Don’t put words in my mouth.