Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Scottish Gaelic
coin
←
Proto-Celtic
*kū
(derived)
←
Welsh
cŵn
(cognate)
←
Cornish
keun
(cognate)
→
Welsh
cŵn
(cognate)