Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Rwanda-Rundi
saa
←
Rwanda-Rundi
isaha
(doublet)
←
Swahili
saa
(borrowed)
→
Rwanda-Rundi
isaha
(doublet)