Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
uhel
←
Proto-Brythonic
*ʉxel
(inherited)
←
Proto-Celtic
*ouxselos
(inherited)
←
Old Breton
uchel
(inherited)
←
Middle Breton
uhel
(inherited)
→
Irish
uachtar
(cognate)
→
Old Irish
úasal
(cognate)