Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Irish
cogain
←
Proto-Celtic
*knāyeti
(derived)
←
Welsh
cnoi
(cognate)
←
Scottish Gaelic
cagainn
(cognate)
←
Proto-Indo-European
*kneh₂-
(derived)
←
Middle Irish
cocnaid
(inherited)
←
Old Irish
con·cná
(inherited)