Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
cyff
←
Proto-Brythonic
*kɨf
(inherited)
←
Latin
cippus
(derived)
←
Middle Irish
cepp
(cognate)
←
Middle Welsh
kyff
(inherited)
←
Middle Breton
queff
(cognate)
→
Welsh
boncyff
(compound)