Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Luxembourgish
eescht
←
German
ernst
(cognate)
←
English
earnest
(cognate)
←
Proto-Germanic
*ernustuz
(inherited)
←
Old High German
ernust
(inherited)