Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Welsh
hi
←
Proto-Celtic
*sī
(inherited)
←
Old Irish
sí
(cognate)
→
Breton
hi
(cognate)
→
Welsh
i
(link)
→
Welsh
ei
(mention)
→
Cornish
hi
(cognate)
→
Old Irish
sí
(cognate)