noun, plural: neutrophiles
(1) A neutrophilic organism that lives and thrives in an environment with a relatively neutral pH
(2) A neutrophil
A neutrophile refers to a neutrophilic organism that lives and thrives in an environment with a relatively neutral pH, i.e. about 6.5 to 7.5.1 The pH is a measure to determine the acidity or alkalinity. The pH of an environment is an important factor in the growth and survival of organisms. Some organisms are sensitive to the pH o their environment and would not be able to thrive if the pH is not within their tolerance range. Thus, it is used as a basis for classifying organisms, particularly the microbes. Microorganisms that prefer an acidic environment are called acidophiles whereas those that prefer an alkaline environment are called alkaliphiles. And, microorganisms that thrive in a neutral environment, i.e. not acidic or alkaline, are called neutrophiles.
A neurtrophile may also pertain to a neutrophil, which is the chief phagocytic leukocyte. It stains with either basic or acid dyes in histological preparations.
1Tortora, G.J., Funke, B.R., and Case, C. L. (2015). Microbiology: An introduction. Benjamin-Cummings Publishing Company, Subs of Addison Wesley Longman, Inc. p. 152.