Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
klevout
←
Proto-Celtic
*klusīti
(inherited)
←
Welsh
clywed
(cognate)
←
Proto-Indo-European
*ḱlew-
(derived)
←
Cornish
klewes
(cognate)