• 佐藤さとう — Sato (common family name)
• 佐官さかん — field officer / mid-ranking military officer
• 佐渡さど — Sado Island
• 補佐ほさ — assistant / aide / advisor

The kanji 佐 is composed of the person radical 亻 (にんべん) and the kanji 左 (left). Historically, the left-hand side represented the position of assistance or support, especially in court ranks. The meaning has evolved to generally signify help or aid.

彼かれは 補佐役ほさやくとして 活躍かつやくしています。
He is playing an active role as an assistant.

佐渡さどは 新潟県にいがたけんの島しまです。
Sado is an island in Niigata Prefecture.

🎧 The reading サ is frequently used in proper nouns and compound words. While no kun-yomi is in common use today, it originally implied “to assist” or “to help.”