Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
porchell
←
Breton
porc'hell
(cognate)
←
Proto-Brythonic
*porxell
(inherited)
←
Cornish
porghel
(cognate)
←
Cornish
porhel
(mention)
←
Latin
porcus
(derived)
←
Middle Welsh
porchell
(inherited)
→
Cornish
porhel
(cognate)