Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Icelandic
systursonur
←
Icelandic
systir
(compound)
←
Icelandic
sonur
(compound)
→
Old English
sweostorsunu
(cognate)