Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Irish
cnú
←
Proto-Celtic
*knūs
(inherited)
←
Proto-Indo-European
*knew-
(inherited)
→
Irish
cnó
(inherited)
→
Scottish Gaelic
cnò
(inherited)
→
Latin
nux
(cognate)