Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Welsh segur
Proto-Brythonic *segʉr (inherited)
Welsh sicr (doublet)
Latin sēcūrus (derived)
Middle Welsh segur (inherited)

Welsh siwr (doublet)
Welsh sicr (doublet)
Welsh segurswydd (link)