Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Central Franconian
hellepe
←
Proto-Germanic
*helpaną
(inherited)
←
Old High German
*helpan
(inherited)
←
Old High German
helfan
(mention)