Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Old Norse
árr
←
Proto-Germanic
*airuz
(inherited)
→
Old English
ar
(cognate)
→
Gothic
𐌰𐌹𐍂𐌿𐍃
(cognate)
→
Old Saxon
er
(cognate)