Dictionary.com

Gram-negative

[ gram-neg-uh-tiv ]
/ ˈgræmˈnɛg ə tɪv /
Save This Word!

adjective (often lowercase)
(of bacteria) not retaining the violet dye when stained by Gram's method.
QUIZ
WILL YOU SAIL OR STUMBLE ON THESE GRAMMAR QUESTIONS?
Smoothly step over to these common grammar mistakes that trip many people up. Good luck!
Question 1 of 7
Fill in the blank: I can’t figure out _____ gave me this gift.

Origin of Gram-negative

First recorded in 1905–10; see origin at Gram's method
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use Gram-negative in a sentence

British Dictionary definitions for Gram-negative

Gram-negative

adjective
designating bacteria that fail to retain the violet stain in Gram's method
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for Gram-negative

gram-negative

Relating to a group of bacteria that do not change color when subjected to the laboratory staining method known as Gram's method or Gram's stain. Gram-negative bacteria have relatively thin cell walls and are generally resistant to the effects of antibiotics or the actions of the body's immune cells. Gram-negative bacteria include E. coli and the bacteria that cause gonorrhea, typhoid fever, rickettsial fever, cholera, syphilis, plague, and Lyme disease. Compare gram-positive.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
FEEDBACK