Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
cyllell
←
Breton
kontell
(cognate)
←
Cornish
kollell
(cognate)
←
Latin
cultellus
(borrowed)
←
Middle Welsh
kyllell
(inherited)
→
Breton
kontell
(cognate)
→
Welsh
cyllall
(link)