Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
gwennol
←
Breton
gwennel
(cognate)
←
Proto-Brythonic
*gwennọl
(inherited)
←
Proto-Celtic
*wesnālā
(inherited)
←
Old Irish
fannall
(cognate)
←
Middle Welsh
gwennawl
(inherited)
→
Welsh
morwennol
(compound)
→
Irish
fáinleog
(cognate)
→
Scottish Gaelic
ainleag
(cognate)