echidnine

from The Century Dictionary.

• noun Serpent-poison; the secretion from the poison-glands of the viper and other serpents.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) The clear, viscid fluid secreted by the poison glands of certain serpents; also, a nitrogenous base contained in this, and supposed to be the active poisonous principle of the virus.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The clear, viscid fluid secreted by the poison glands of certain snakes.
• noun organic chemistry A nitrogenous base contained in this fluid, believed to be the active poisonous principle of the virus.