Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
ionadh
←
Proto-Celtic
*angnātos
(inherited)
←
Old Irish
ingnad
(inherited)
→
Irish
iontas
(mention)
→
Irish
iontach
(mention)