Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Cumbric
gos
←
Breton
gwaz
(cognate)
←
Proto-Celtic
*wastos
(inherited)
←
Welsh
gwas
(cognate)
←
Old Irish
foss
(cognate)