Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
kevelek
←
Breton
kefeleg
(cognate)
←
Proto-Brythonic
*kėfɨlọg
(inherited)
←
Proto-Brythonic
*kėfɨl
(mention)
←
Middle Cornish
kyvelak
(inherited)
←
Welsh
cyffylog
(cognate)
→
Breton
kefeleg
(cognate)
→
Welsh
cyffylog
(cognate)