• 佐藤さとう — Sato (common family name)
• 佐渡さど — Sado Island
• 補佐ほさ — assistant / aide / advisor
• 大佐たいさ — colonel (military rank)
• 少佐しょうさ — major (military rank)

佐 combines the person radical 亻にんべん with 左ひだり. In ancient court ranks, the left side was associated with support or secondary positions. Over time, 佐 came to mean help, assistance, or supportive roles, and today it is also widely seen in family names.