Important
Valuable, Serious Matter
noun, な adjective
A big action means something big is going down. This is no ordinary action. It is an action that is important.
だいじ
This is a jukugo word, which usually means on'yomi readings from the kanji. Since 大 has two on'yomi readings, here's a mnemonic to help you remember which one to use:
Nothing in your life is as important or valuable to you as dyes (だい). You really just love dyes more than anything else. Dyes, dyes, dyes!
大事なのは、きちんとあいさつをすることです。
The important thing is to greet them properly.
日本ごのべんきょうのために、毎日ワニカニにログインしてレビューをするのはとても大事なことです。
Logging onto WaniKani and doing your reviews every day is very important for your Japanese learning.
リラックスする時間をとることは、とても大事だよ。
Taking time to relax is important.