Source : Webster's Revised Unabridged Dictionary (1913)

Antitoxin \An`ti*tox"in\, Antitoxine \An`ti*tox"ine\, n. [Pref.
   anti- + toxin.]
   A substance (sometimes the product of a specific
   micro-organism and sometimes naturally present in the blood
   or tissues of an animal), capable of producing immunity from
   certain diseases, or of counteracting the poisonous effects
   of pathogenic bacteria.