Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
hanter
←
Proto-Celtic
*santeros
(inherited)
←
Welsh
hanner
(cognate)
→
Breton
hanter-kant
(compound)
→
Welsh
hanner
(cognate)
→
Ancient Greek
ἕτερος
(cognate)