Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
cnoi
←
Proto-Celtic
*knāyeti
(inherited)
←
Proto-Indo-European
*kneh₂-
(inherited)
←
Middle Welsh
cnoi
(inherited)
←
Middle Welsh
cny
(mention)
→
Welsh
cnofil
(compound)
→
Welsh
cnofa
(affix)
→
Irish
cogain
(cognate)