Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
pluv
←
Proto-Indo-European
*plews-
(derived)
←
Latin
plūma
(borrowed)
→
Cornish
pluven
(affix)