Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Old Church Slavonic ѥдинъ

→ Bulgarian веднъж (mention)
→ Ancient Greek οἴνη (cognate)
→ Latin unus (cognate)
→ Latvian viens (cognate)
→ Russian единый (derived)
→ Russian воедино (affix)
→ Ukrainian єдиний (derived)