1. the act or an instance of inoculating, especially the introduction of an antigenic substance or vaccine into the body to produce immunity to a specific disease.
2. informal A preemptive advertising tactic in which one party attempts to foresee and neutralize potentially damaging criticism from another party by being the first to confront troublesome issues.

1. the introduction of an antigenic substance or vaccine into the body to produce immunity to a specific disease.
2. the introduction of a microorganism into a culture medium.
3. an inoculum, what is inoculated

1. the act or art of inoculating trees or plants.
2. the act or practice of communicating a disease to a person in health, by inserting contagious matter in his skin or flesh, usually for the purpose of inducing immunity to the disease.
3. fig.: the communication of principles, especially false principles, to the mind.
4. the introduction of microorganisms into a growth medium, to cause the growth and multiplication of the microorganisms.

1. the act or practice of grafting by budding.
2. hence the ingrafting of any minute germ in a soil where it will grow; especially, the act or practice of communicating disease by introducing through puncture infectious matter into the tissues; the introduction of a specific animal poison into the tissues by puncture or through contact with a wounded surface; specifically, in medicine, the direct insertion of the virus of smallpox in order, by the production of a mitigated form of it, to prevent a more severe attack of the disease in the natural way.
3. vaccination against disease, as against smallpox, anthrax, rinderpest, and to some extent against typhoid fever, plague, dysentery, etc.

1. taking a vaccine as a precaution against contracting a disease