n. [ L. inoculatio: cf. F. inoculation. ] 1. The act or art of inoculating trees or plants. [ 1913 Webster ]

2. (Med.) 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. [ 1913 Webster +PJC ]

☞ The use was formerly limited to the intentional communication of the smallpox, but is now extended to include any similar introduction of modified virus; as, the inoculation of rabies by Pasteur. The organisms inoculated are usually an attentuated form of the disease-causing organism, which may multiply harmlessly in the body of the host, but induce immunity to the more virulent forms of the organism. [ 1913 Webster +PJC ]

3. Fig.: The communication of principles, especially false principles, to the mind. [ 1913 Webster ]

4. (Microbiology) The introduction of microorganisms into a growth medium, to cause the growth and multiplication of the microorganisms. [ PJC ]