Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Manx
booa
←
Proto-Celtic
*bāus
(inherited)
←
Proto-Indo-European
*gʷṓws
(inherited)
←
Old Irish
bó
(inherited)
→
Breton
buoc'h
(cognate)