Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
den
←
Proto-Brythonic
*dün
(inherited)
←
Proto-Celtic
*gdonyos
(inherited)
←
Proto-Indo-European
*dʰéǵʰom-yo-
(inherited)
←
Proto-Indo-European
*dʰéǵʰōm
(mention)
→
Breton
denelezh
(suffix)
→
Old Irish
duine
(cognate)