Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
inunn
←
Proto-Celtic
*sindos
(mention)
←
Old Irish
in
(mention)
←
Old Irish
sin
(mention)
←
Old Irish
sund
(mention)
→
Irish
ionann
(inherited)
→
Scottish Gaelic
ionann
(inherited)