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.
重要なのは、元気でいることです。
The important thing is to be healthy.
小学生の時、私は学校で友達を作ることが重要だと思っていました。
When I was in elementary school, I thought it was important to make friends at school.
それは、国民にとって重要なお知らせでした。
It was an important announcement for the people.