Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
eidheann
←
Proto-Celtic
*ɸedennos
(inherited)
←
Old Irish
eidenn
(inherited)
→
Irish
eidhneachán
(affix)
→
Irish
eidhneán
(affix)
→
Irish
eidhneach
(affix)