Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cornish
kavos
←
Breton
kaout
(mention)
←
Breton
kavout
(mention)
←
Breton
kavout
(cognate)
←
Welsh
cael
(cognate)
→
Breton
kavout
(cognate)
→
Welsh
cael
(cognate)