It's all Greek to me

Lecturer(writing on board):...Thus we can easily determine the meaning of the word from the following semantic analysis..the initial participle in the word "democracy" comes from the latin word, "demos", meaning "the people"...
Greek student(interrupting): That's a greek word, actually.
L: Is it?
GS:Yes.
L:Are you sure?
GS: Yes.
L: I have never been corrected on that one before.