吸 means to draw in, to inhale and is a JLPT N3 kanji. It has 6 strokes and uses the Mouth radical (口).
Stroke order · 6 strokes
On'yomi (音読み)
キュウ
Kun'yomi (訓読み)
す(う)
Radical
口 · Mouth
Strokes
6
How to remember 吸
Drawing something in (及) through the mouth (口) — like sipping juice through a straw. 吸う means to breathe in or to smoke — better to only do the former.