Busy
noun, な adjective
If you've had many busy days, then you're even more busy than you thought!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
最近多忙でつかれていて、よく舌がもつれるんです。
I've been tired because of how busy I've been lately, and it's been making me tongue tied.
多忙な生活を送っています。
I lead a busy life.
ご多忙な所申し訳無いんですが、少しの間代わりに列の順番を取っておいてもらえませんか?
I know how busy you are, and I feel terrible asking this, but would you mind saving my place in line for a few minutes?