Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
chwaeth
←
Proto-Celtic
*swexto-
(derived)
←
Proto-Indo-European
*swekʷto-
(derived)
←
Proto-Indo-European
*sokʷós
(mention)
←
Old Welsh
chweith
(inherited)
→
Welsh
chwaith
(mention)