厶 sī private; secret; selfish
Made with 2 strokes.
A picture of a nose. Pointing to one's nose indicates 'self'.
Ancient small seal form 

Sounds same
丝 sī (silk) 纟 sī (silk) 思 sī (to think)Different tone
死 sǐ (die) 四 sì (four) 巳 sì (snake) 跑 sì (to run) 寺 sì (Buddhist temple)Radical
Index 28 used in: 公 gōng (public) ; 么 me (what) ; 能 néng (to be able to) ; 去 qù (go) ; 台 tái (typhoon) ; 雄 xióng (male) ; 云 yún (cloud) ; 至 zhì (to arrive)
Stroke order for character 厶, kindly provided under Wikimedia creative commons license ➚