Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
llestr
←
Breton
lestr
(cognate)
←
Proto-Brythonic
*llestr
(inherited)
←
Proto-Celtic
*lestrom
(inherited)
←
Irish
leastar
(cognate)
→
Breton
lestr
(cognate)
→
Irish
leastar
(cognate)