ni·​dus | \ ˈnī-dəs How to pronounce nidus (audio) \
plural nidi\ ˈnī-​ˌdī How to pronounce nidus (audio) \ or niduses

Definition of nidus

1 : a nest or breeding place especially : a place or substance in an animal or plant where bacteria or other organisms lodge and multiply
2 : a place where something originates, develops, or is located

Did you know?

Nidus literally means "nest" in Latin, and some of its relatives in English suggest this connection in a straightforward way. For example, we have nidification for the process of building a nest, and nidicolous, meaning "reared in a nest." But nidus itself, when used as an English word, is apt to refer to a place where bacteria lodge and multiply. Consequently, the extended use of nidus in English often has a negative connotation referring to a source of undesirable opinions or behaviors.

Examples of nidus in a Sentence

a type of contact lens that proved to be a nidus of infection
Recent Examples on the Web The indisputably desirable goal of supporting walking, biking and bus-riding around an Uptown nidus was severely wounded. Star Tribune, 30 Nov. 2020

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

First Known Use of nidus

1734, in the meaning defined at sense 1

History and Etymology for nidus

New Latin, from Latin

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Cite this Entry

“Nidus.” Dictionary, Merriam-Webster, Accessed 7 Oct. 2022.

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More Definitions for nidus


ni·​dus | \ ˈnī-dəs How to pronounce nidus (audio) \
plural nidi\ -​ˌdī How to pronounce nidus (audio) \ or niduses

Medical Definition of nidus

: a place where something originates or is fostered or develops specifically : the point of origin or focus of an infection or disease process


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