Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Breton
Lun
←
Welsh
dydd Llun
(cognate)
←
Cornish
de Lun
(cognate)
←
Latin
lūna
(borrowed)