Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
English
Dagda
←
Proto-Celtic
*Dago-deiwos
(derived)
←
Proto-Indo-European
*dʰagʰo-
(derived)
←
Proto-Indo-European
*dʰegʷʰ-
(mention)
←
Proto-Indo-European
*deywós
(mention)
←
Middle Irish
Dagda
(mention)
←
Old Irish
Dagdae
(derived)