Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
gwadd
←
Breton
goz
(cognate)
←
Cornish
godh
(cognate)
→
Breton
goz
(link)
→
Westrobothnian
gwann
(cognate)