Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Luxembourgish
klappen
←
German
klopfen
(cognate)
←
Middle High German
klopfen
(inherited)
←
Old High German
klophōn
(inherited)