Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle Irish
reithinech
←
Middle Irish
reithine
(affix)
←
Middle Irish
-ach
(affix)
←
Old Irish
roithinech
(inherited)