Conversation

Some historic UK doctor (who was educated for greek and latin), i have a new disease to name ... ill call it "osteoarthritis" ~ my broken translation, "bone joint itus".

Some Deutsche Arzt reading the paper. ... ok its "arthrose".

um?

pls can linguists explain why DE can be short **when it wants to**. Isn't a disease name classified as a Noun?
Hopefully this disease isn't spoken about everyday, so 'maximising concise' isn't an important design criteria on that word.