Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
ysgyfarn
→
Breton
skouarn
(cognate)
→
Welsh
ysgyfarnog
(affix)
→
Cornish
skovarn
(cognate)