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

→ Breton dek (inherited)
→ Welsh deg (inherited)
→ Irish deich (inherited)
→ Scottish Gaelic deich (inherited)
→ Manx jeih (inherited)
→ Cornish deg (inherited)
→ Old Irish deich (inherited)