Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Irish ríon
Proto-Celtic *rīganī (inherited)
Old Irish rígain (inherited)

Irish banríon (prefix)
Irish ríonmháthair (affix)
Scottish Gaelic rìbhinn (cognate)
Manx rein (cognate)