• 首くび — neck
• 首都しゅと — capital city
• 部首ぶしゅ — radical
• 首相しゅしょう — prime minister
• 首輪くびわ — collar
• 自首じしゅ — voluntary surrender
• 首脳しゅのう — leader; head (of a government/organization)

The kanji 首 is a pictograph of a head seen from above. It originally depicted features like hair or facial structure, and now it symbolizes the head or leader of something.