Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
ffenestr
←
Breton
prenestr
(cognate)
←
Cornish
fenester
(cognate)
←
Latin
fenestra
(borrowed)
→
Breton
prenestr
(cognate)