Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*ɸarsketi
→
Old Irish
tochmarc
(derived)
→
Old Irish
immcomairc
(derived)
→
Middle Welsh
arch
(inherited)
→
Middle Welsh
erchi
(inherited)
→
Middle Welsh
erchi
(inherited(wlm/cy))