Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
English
-athon
←
English
marathon
(back-formation)
→
English
yogathon
(affix)
→
English
wankathon
(affix)
→
English
blogathon
(affix)