Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*sentus
→
Breton
hent
(inherited)
→
Welsh
hynt
(inherited)
→
Irish
séad
(inherited)
→
Old Irish
sét
(inherited)