Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
cynnud
←
Breton
keuneud
(cognate)
←
Proto-Celtic
*kom-daw-to-
(inherited)
←
Proto-Celtic
*kom-dawyo-
(mention)
←
Welsh
cynnau
(mention)
←
Welsh
cynnau
(mention)
←
Cornish
kunys
(cognate)
→
Welsh
cynuta
(affix)