Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
glin
←
Proto-Brythonic
*glin
(inherited)
←
Proto-Celtic
*glūnos
(inherited)
←
Proto-Celtic
*gnūn-
(mention)
←
Proto-Celtic
*gnūnos
(mention)
←
Proto-Indo-European
*ǵónu
(inherited)
←
Old Irish
glún
(cognate)
→
Irish
glúin
(cognate)