Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Celtic
*wolk-
→
Welsh
golhi
(inherited(cy/kw))
→
Welsh
golchi
(inherited)
→
Scottish Gaelic
failc
(derived)