Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
tas
←
Proto-Brythonic
*tad
(inherited)
←
Proto-Celtic
*tatos
(inherited)
→
Cornish
tasow
(suffix)
→
Cornish
tas-gwynn
(affix)
→
Latin
tata
(mention)