Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
cearc
←
Proto-Celtic
*kerkā
(inherited)
←
Old Irish
cerc
(inherited)
→
Irish
circeoil
(affix)
→
Irish
corr
(mention)
→
Irish
gearrchearc
(prefix)
→
Ancient Greek
κρέξ
(cognate)