Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
mwyar
←
Breton
mouar
(cognate)
←
Proto-Brythonic
*muɨar
(inherited)
←
Proto-Celtic
*smiyoros
(inherited)
←
Irish
sméar
(cognate)
←
Cornish
mor
(cognate)
→
Welsh
mwyara
(affix)
→
Irish
sméar
(cognate)
→
Scottish Gaelic
smeur
(cognate)