Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Bourguignon
chaifaud
←
Old French
chafaud
(inherited)
←
Bourguignon
échaifaud
(doublet)
→
Bourguignon
échaifaud
(doublet)