The word nosferatu is used as a synonym for vampire, but it can also mean 'undead'. Nevertheless, its origin is somehow shrouded in mystery, the word itself became widely known because of Bram Stoker's Dracula, in which he uses it as a synonym for undead in Romanian. There are several theories of the real meaning of the word and its origin however there does not seem to be one that is fully correct; the least unlikely being a portmanateu of "Necuratu" ("unclean spirit") and "Nosophoros" ("bringer of plague").
The term "Nosferatu" was used by a German movie studio in 1922 in an attempt to avoid paying royalties when adopting Stoker's Dracula story which ended in bankruptcy after losing the copyright lawsuit to Stoker's widow. This whole event revived the popularity of both Nosferatu and Dracula.