Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Proto-Indo-European *reǵ-

→ English retch (derived)
→ English rink (derived)
→ English rax (derived)
→ English rackan (derived)
→ Old English recen (derived)
→ Old English racente (derived)
→ Latvian redzēt (mention)
→ Swedish regn (mention)