Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
rún
←
Proto-Celtic
*rūnā
(inherited)
←
Welsh
rhin
(cognate)
←
Scottish Gaelic
rùn
(cognate)
←
Manx
roon
(cognate)
←
Old Irish
rún
(inherited)
→
Irish
rúnaí
(suffix)
→
Irish
rúnda
(affix)