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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The team focused its search for a new drug on compounds that suppress the Lol system, which shuttles lipoproteins between the inner and outer membranes in gram-negative bacteria. Tribune News Service, The Mercury News, 20 June 2024 Bacteria populations in the average human gut are roughly split between gram-negative and gram-positive types, said Kristen Munoz, a former doctoral student at the University of Illinois who co-led the study. Corinne Purtill, Los Angeles Times, 12 June 2024 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

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 21 Dec. 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
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!