Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
fearnóg
←
Proto-Celtic
*wernā
(inherited)
←
Welsh
gwern
(cognate)
←
Irish
fern
(affix)
←
Irish
-óg
(affix)
←
Scottish Gaelic
feàrna
(cognate)
←
Manx
farney
(cognate)
→
Scottish Gaelic
feàrna
(cognate)
→
Manx
farney
(cognate)