Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
celu
←
Proto-Brythonic
*kelɨd
(inherited)
←
Proto-Celtic
*keleti
(inherited)
←
Proto-Indo-European
*ḱéleti
(inherited)
←
Old Irish
ceilid
(cognate)
→
Welsh
datgelu
(prefix)
→
Irish
ceil
(cognate)