Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Gaulish
suados
←
Proto-Celtic
*swādus
(inherited)
←
Proto-Indo-European
*sweh₂dus
(inherited)
←
Latin
suādus
(cognate)
←
Latin
suāvis
(mention)
←
Middle Irish
sadh
(cognate)