gram-negative

adjective

gram-neg·​a·​tive ˈgram-ˈne-gə-tiv How to pronounce gram-negative (audio)
: not holding the purple dye when stained by Gram's stain
used chiefly of bacteria

Examples of gram-negative in a Sentence

Recent Examples on the Web Encased in both an inner and outer membrane that antibiotics struggle to cross, gram-negative bacteria are resistant to most currently available therapies. Corinne Purtill, Los Angeles Times, 3 Jan. 2024 Shigella bacteria are gram-negative bacteria, shaped like rods, recognized worldwide as the most common cause of dysentery, a gastrointestinal illness resulting in severe diarrhea. CBS News, 1 Mar. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'gram-negative.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1907, in the meaning defined above

Time Traveler
The first known use of gram-negative was in 1907

Dictionary Entries Near gram-negative

Cite this Entry

“Gram-negative.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/gram-negative. Accessed 29 Mar. 2024.

Medical Definition

gram-negative

adjective
gram-neg·​a·​tive ˈgram-ˈneg-ət-iv How to pronounce gram-negative (audio)
: not holding the purple dye when stained by Gram's stain
used chiefly of bacteria
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