Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Manx
castan
←
French
châtaigne
(cognate)
←
Old French
chastaigne
(derived)
←
Irish
castán
(cognate)
←
Manx
-an
(affix)
←
Latin
castanea
(derived)
←
Old Irish
castán
(inherited)