Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
chwant
←
Breton
c'hoant
(cognate)
←
Cornish
hwans
(cognate)
→
Welsh
trachwant
(affix)
→
Old Irish
sét
(cognate)