Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
bos
→
Breton
bezañ
(cognate)
→
Welsh
bod
(cognate)
→
Cornish
esedhvos
(affix)
→
Cornish
godhvos
(mention)