• 祖先そせん — ancestor
• 祖国そこく — homeland
• 先祖せんぞ — ancestors
• 祖母そぼ — grandmother
• 祖父そふ — grandfather
• 開祖かいそ — founder of a school or tradition
• 元祖がんそ — originator, pioneer

The left side, 礻(shimesuhen), relates to ritual or spirit, while the right part is 且, which once resembled a tray or altar. Together they suggest reverence toward ancestors, hence the meaning of "ancestor" or "originator."

祖先そせんに 感謝かんしゃする 文化ぶんかがあります。
There is a culture of expressing gratitude to ancestors.

祖国そこくを 離はなれて 暮くらしています。
I live away from my homeland.

Typically read as ソ in compound words like 祖父, 祖母, and 祖国. It does not have a common kun-yomi reading.