Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
English
Erc
←
Proto-Celtic
*ɸerkos
(derived)
←
Irish
Earc
(cognate)
←
Proto-Indo-European
*perḱ-
(derived)
←
Old Irish
Erc
(derived)