Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Middle Irish
slúagh
←
Proto-Celtic
*slougos
(inherited)
←
Old Irish
slóg
(inherited)
→
Irish
slua
(inherited)
→
Scottish Gaelic
sluagh
(inherited)