bane. n.
1. Fatal injury or ruin: “Hath some fond lover tic'd thee to thy bane?” (George Herbert).
2. A cause of harm, ruin, or death: “Obedience,/Bane of all genius, virtue, freedom, truth,/Makes slaves of men” (Percy Bysshe Shelley).
3. A source of persistent annoyance or exasperation: “The spellings of foreign names are often the bane of busy copy editors” (Norm Goldstein).
4. A deadly poison.
from: http://dictionary.reference.com/