microorganism

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noun mi·cro·or·gan·ism \-ˈȯr-gə-ˌni-zəm\

Definition of microorganism

  1. :  an organism (such as a bacterium or protozoan) of microscopic or ultramicroscopic size

Recent Examples of microorganism from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'microorganism'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of microorganism

International Scientific Vocabulary


MICROORGANISM Defined for English Language Learners

microorganism

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noun

Definition of microorganism for English Language Learners

  • biology : an extremely small living thing that can only be seen with a microscope


MICROORGANISM Defined for Kids

microorganism

play
noun mi·cro·or·gan·ism \ˌmī-krō-ˈȯr-gə-ˌni-zəm\

Definition of microorganism for Students

  1. :  a living thing (as a bacterium) that can only be seen with a microscope


Medical Dictionary

microorganism

play
noun mi·cro·or·gan·ism \-ˈȯr-gə-ˌniz-əm\

Medical Definition of microorganism

  1. :  an organism of microscopic or ultramicroscopic size



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