Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
gram-negative is an adjective meaning "(of bacteria) being of or relating to a bacterium that does not retain the violet stain used in Gram's method". It carries one recorded sense.
(of bacteria) being of or relating to a bacterium that does not retain the violet stain used in Gram's method
bacteria
Definitions, synonyms and semantic relations for gram-negative come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.