Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
gwad
←
Proto-Celtic
*waytos
(inherited)
←
Welsh
gwaed
(cognate)
←
Cornish
gwythi
(mention)
←
Cornish
goes
(cognate)
→
Breton
gwadgi
(compound)
→
Welsh
gwaed
(cognate)
→
Cornish
goes
(cognate)
→
Cornish
goos
(cognate)