Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
kilhog
←
Proto-Brythonic
*kėljọg
(inherited)
←
Proto-Celtic
*kalyākos
(inherited)
←
Proto-Indo-European
*kleh₁-
(derived)
←
Old Breton
kelihuc
(inherited)