Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
gwydn
→
Cornish
sira-wydn
(affix)
→
Cornish
tasow-wydn
(affix)
→
Cornish
dama-wydn
(affix)