Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
salach
←
Proto-Celtic
*salākos
(inherited)
←
Old Irish
sal
(affix)
←
Old Irish
-ach
(affix)
→
Irish
salach
(inherited)
→
Scottish Gaelic
salach
(inherited)