Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
stêr
←
Proto-Celtic
*stagrā
(inherited)
←
Ancient Greek
στάζω
(cognate)
←
Proto-Indo-European
*steh₂g-
(inherited)
←
Latin
stāgnum
(cognate)
←
Old Breton
staer
(inherited)
→
Breton
stêrioù
(suffix)