Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Irish each
Proto-Celtic *ekʷos (inherited)
Proto-Indo-European *h₁éḱwos (inherited)
Old Irish ech (inherited)

English jockey (mention)
English Hearn (mention)
English Ahern (mention)
English McCafferty (mention)
English McEachern (mention)
English Donaghey (mention)
Old English eoh (cognate)
Irish láir (link)
Irish eachlann (affix)
Irish eachaí (affix)
Irish eachaí (affix)
Irish eachaire (mention)
Irish each-chumhacht (affix)
Irish eachra (affix)
Irish Eochaidh (cognate)
Old Norse jór (cognate)