/vak"seuh nayt'/ , v. , vaccinated, vaccinating . Med.
v.t.
1. to inoculate with the vaccine of cowpox so as to render the subject immune to smallpox.
2. to inoculate with the modified virus of any of various other diseases, as a preventive measure.
v.i.
3. to perform or practice vaccination.
[ 1800-10; back formation from VACCINATION ]