欠 means absence; lack and is a JLPT N3 kanji. It has 4 strokes and uses the open mouth / lack radical (欠).
Stroke order · 4 strokes
On'yomi (音読み)
ケツ、ケン
Kun'yomi (訓読み)
か(ける)
Radical
欠 · open mouth / lack
Strokes
4
How to remember 欠
A picture of a person yawning with mouth open — yawning through class day after day until one day they just don't show up. 欠席 (absence) — teachers' favorite word for the attendance book.