Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
serc
←
Proto-Celtic
*sterkā
(inherited)
→
Irish
searc
(inherited)
→
Irish
déirc
(mention)
→
Scottish Gaelic
seirc
(inherited)
→
Old Irish
sercaid
(affix)
→
Old Irish
sercach
(affix)