Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
leue
←
Proto-Celtic
*laygos
(inherited)
←
Welsh
llo
(cognate)
←
Cornish
leugh
(cognate)
←
Old Irish
lóeg
(cognate)
→
Breton
leueoù
(suffix)
→
Welsh
llo
(cognate)