Cemetary is not easy to spot as Greek origin word but if you know that in Greek word for cemetery is κοιμητήριον (kimitirion) you can easily spot the origin. But what really means κοιμητήριον;
Verb sleep in Greek is κοιμάμαι (kimame) therefore cemetary is the place people sleep. Probably this applies to Christians that they will raise after the 2nd Coming, so I speculate that this word is later than the word νεκροταφείο that translates to graveyard.