Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Norse
þváttr
←
Proto-Germanic
*þwahtuz
(inherited)
←
Old Norse
þvá
(mention)
→
Icelandic
þvottur
(derived)
→
Swedish
tvätta
(derived)
→
Swedish
tvätt
(derived)