vaccinationEnglishOxford New American Dictionaryvaccination /ˌvaksəˈnāSH(ə)n, ˌvæksəˈneɪʃ(ə)n / ▸ noun treatment with a vaccine to produce immunity against a disease; inoculation: vaccination against yellow fever is essential [count noun] if you think you need a flu vaccination, check with your doctor.