Wordnet 3.0
NOUN (1)
1.
(fairytale) a monstrous villain who marries seven women;
he kills the first six for disobedience;
The Collaborative International Dictionary of English v.0.48:
Bluebeard \Blue"beard\, n.
The hero of a medi[ae]val French nursery legend, who, leaving
home, enjoined his young wife not to open a certain room in
his castle. She entered it, and found the murdered bodies of
his former wives. -- Also used adjectively of a subject which
it is forbidden to investigate.
[1913 Webster]
The Bluebeard chamber of his mind, into which no eye
but his own must look. --Carlyle.
[1913 Webster]
WordNet (r) 3.0 (2006):
Bluebeard
n 1: (fairytale) a monstrous villain who marries seven women; he
kills the first six for disobedience