microbiologyPronunciation: /ˌmʌɪkrə(ʊ)bʌɪˈɒlədʒi/Definition of microbiology noun [mass noun] the branch of science that deals with microorganisms. Derivatives microbiologicalPronunciation: /-bʌɪəˈlɒdʒɪk(ə)l/ adjective microbiologicallyPronunciation: /-bʌɪəˈlɒdʒɪk(ə)li/ adverb microbiologist noun microbiology in other Oxford dictionaries Definition of microbiology in the US English dictionary