• 共通きょうつう — common / shared
• 共感きょうかん — empathy
• 公共こうきょう — public / communal
• 共存きょうぞん — coexistence
• 共演きょうえん — co-starring / joint performance
• 共同きょうどう — collaboration / partnership

This kanji depicts hands offering or holding something together, conveying the idea of sharing and acting in unison. Hence its frequent use in words about partnership, unity, and mutual action.