Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
ymennydd
←
Breton
empenn
(cognate)
←
Proto-Celtic
[[*en|*en-]][[*kʷennom|kʷennio-]]
(inherited)
←
Welsh
yn
(compound)
←
Welsh
pen
(compound)
←
Irish
inchinn
(cognate)