Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
ffa
←
Breton
fav
(cognate)
←
Breton
fao
(mention)
←
Proto-Brythonic
*fav
(inherited)
←
Cornish
faf
(cognate)
←
Cornish
fa
(mention)
←
Latin
faba
(derived)
←
Middle Welsh
ffa
(inherited)