Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
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Welsh poeth
Proto-Brythonic *poɨθ (inherited)
Proto-Celtic *kʷoxtos (inherited)
Proto-Indo-European *pekʷ- (root)
Proto-Indo-European *pekʷ- (derived)

Welsh poethwel (link)
Welsh danadl poethion (compound)