Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
hep
←
Proto-Celtic
*sekʷo
(inherited)
←
Welsh
heb
(cognate)
←
Proto-Indo-European
*sekʷ-
(derived)