Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
comhaireamh
←
Proto-Celtic
*rīmā
(derived)
←
Irish
comh-
(affix)
←
Irish
áireamh
(affix)
←
Middle Irish
comáirem
(inherited)
→
Irish
comhair
(back-formation)