Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Irish bac
← Proto-Celtic *bakkos (inherited)
← Old Irish bacc (inherited)
← Old Irish baccaid (inherited)

→ English peg (cognate)
→ English nabocklish (mention)
→ Irish bacadh (affix)
→ Irish bacóireacht (affix)
→ Irish closbhac (affix)
→ Irish aerbhac (affix)