Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
immsoí
←
Proto-Celtic
*ambisuweti
(inherited)
←
Old Irish
imm-
(affix)
←
Old Irish
soïd
(affix)