Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Icelandic
tjörn
←
Proto-Germanic
*ternō
(inherited)
←
Old Norse
tjǫrn
(inherited)
→
English
tarn
(cognate)
→
Icelandic
tjarnastör
(affix)
→
Icelandic
tjarnablaðka
(affix)
→
Norwegian Bokmål
tjern
(cognate)