Definition of "toxoid" [tox•oid]

• A substance that has been treated to destroy its toxic properties but retains the capacity to stimulate production of antitoxins, used in immunization. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Several vaccines are made by taking toxins and inactivating them with a chemical (the toxin, once inactivated, is called a toxoid)."
• "Purify a toxin produced by the bacteria (toxoid vaccine), e.g., diphtheria, tetanus, and pertussis"
• "Once injected, the toxoid elicits an immune response against the toxin, but, unlike the toxin, doesn't cause disease."