逆 means reverse, opposite and is a JLPT N2 kanji. It has 9 strokes and uses the movement / road radical (⻌).
Stroke order · 9 strokes
On'yomi (音読み)
ギャク、ゲキ
Kun'yomi (訓読み)
さか
Radical
⻌ · movement / road
Strokes
9
How to remember 逆
On the road (⻌) a person walks facing the wrong way — opposite to everyone else. 逆 (reverse), 逆さま (upside down) — a photo hung 逆さま always gets a laugh.