Definitions

merriam-webster.com:

1: the reanimated body of a dead person believed to come from the grave at night and suck the blood of persons asleep

2 a: one who lives by preying on others b: a woman who exploits and ruins her lover

3: vampire bat

 

 

dictionary.com:

vam·pire   // ", "6"); interfaceflash.addParam("loop", "false"); interfaceflash.addParam("quality", "high"); interfaceflash.addParam("menu", "false"); interfaceflash.addParam("salign", "t"); interfaceflash.addParam("FlashVars", "soundUrl=http%3A%2F%2Fcache.lexico.com%2Fdictionary%2Faudio%2Fluna%2FV00%2FV0022500.mp3"); interfaceflash.write(); // ]]>  Audio Help   /ˈvæmpaɪər/ Pronunciation Key - Show Spelled Pronunciation[vam-pahyuhr] Pronunciation Key - Show IPA Pronunciation

–noun 1. a preternatural being, commonly believed to be a reanimated corpse, that is said to suck the blood of sleeping persons at night. 2. (in Eastern European folklore) a corpse, animated by an undeparted soul or demon, that periodically leaves the grave and disturbs the living, until it is exhumed and impaled or burned. 3. a person who preys ruthlessly upon others; extortionist. 4. a woman who unscrupulously exploits, ruins, or degrades the men she seduces. 5. an actress noted for her roles as an unscrupulous seductress: the vampires of the silent movies.

as we can see, the word is used for many things. I believe firmly that people like me, who feed on others in a literal sense, are the ones who were originally given this name