Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
cyfrin
←
Proto-Brythonic
*kuβ̃rin
(inherited)
←
Proto-Celtic
*kom-
(derived)
←
Proto-Celtic
*rūnā
(mention)
→
Welsh
cyfrinach
(affix)
→
Welsh
cyfriniol
(affix)
→
Welsh
cyfrinair
(affix)