Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
arar
←
Proto-Brythonic
*aradr
(inherited)
←
Proto-Celtic
*aratrom
(inherited)
←
Proto-Indo-European
*h₂érh₃trom
(inherited)
←
Middle Breton
arazr
(inherited)