Absence
Nonattendance
noun, verbal noun
When a seat is lacking the person it's supposed to have in it, there is an absence. Where is Johnny? Another absence? Ugh. Johnny. C'mon.
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. Note that the けつ is shortened to けっ as つs often are when in a situation like this.
今日は薬学はかせは欠席なんですね。
The pharmacy department is absent today, eh?
無だん欠席が三回つづいたので、首にしました。
I fired him because he no call no show'd three times in row.
大変申し訳ないのですが、急な出張が入ってしまったので、今夜の同窓会は欠席させて頂きます。
I’m terribly sorry, but an urgent business trip has come up, so I’ll be absent from the reunion party tonight.