Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
dâ
←
Proto-Brythonic
*daɣ
(inherited)
←
Proto-Celtic
*dagos
(inherited)
←
Irish
dea-
(cognate)