Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle Irish
faílenn
←
Breton
gouelan
(cognate)
←
Proto-Celtic
*wailannā
(inherited)
←
Welsh
gwylan
(cognate)
←
Cornish
guilan
(cognate)
←
Old Irish
foílenn
(inherited)
→
Irish
faoileog
(mention)
→
Scottish Gaelic
faoileag
(mention)