Needed, Essential
Noun and な adjective
ひつよう
バスをおりてから、少し歩く必要があります。
I have to walk a little while after getting off the bus.
JETのめんせつに合かくするために必要なことって何ですか。
What is necessary to pass the JET interview?
日本に行ったら必要になるものって何だろう？
What would I need if I went to Japan?
It's certain that you need it. This thing is necessary. It is needed.
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.