Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Scottish Gaelic
rùsg
←
Proto-Celtic
*rūsklo-
(derived)
←
Welsh
rhisgl
(cognate)
←
Old Irish
rúsc
(inherited)
→
Irish
rúsc
(cognate)