nod·ule | \ˈnä-(ˌ)jül \

Definition of nodule 

: a small mass of rounded or irregular shape: such as

a : a small rounded lump of a mineral or mineral aggregate

b : a swelling on a leguminous root that contains symbiotic bacteria

c : a small abnormal knobby bodily protuberance (such as a tumorous growth or a calcification near an arthritic joint)

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Synonyms for nodule


bump, knot, lump, node, swelling

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Examples of nodule in a Sentence

The examination revealed a nodule on his lung. a nodule on the leaf indicated that a worm had laid eggs there

Recent Examples on the Web

These nodules can range from very small to very large and may grow fast. Texas A&m University, Houston Chronicle, "Pet Talk: Mammary tumors in dogs," 20 June 2018 Once a vine quits producing, cut it off at ground level, leaving the nitrogen-rich root nodules in the ground to aid the growth of a following crop, such as brassicas, carrots, beets, or beans. The Editors Of Organic Life, Good Housekeeping, "Growing Peas Has Never Been Easier Than This," 31 Mar. 2017 These plants collaborate with soil bacteria to absorb nitrogen from the air and deposit it in tiny root nodules—a process called nitrogen fixation. Beth Hanson, Good Housekeeping, "Grow Healthier Crops Using These Natural Nitrogen Sources," 24 Aug. 2015 Many plants are equally dependent on microbes: peas, clover, soy, and beans have nodules on their roots that host bacteria, fixing nitrogen from the air in the plant. Jason Pontin, WIRED, "The 19th-Century Crank Who Tried to Tell Us About the Microbiome," 15 June 2018 The plants build specialized structures on their roots called nodules to house and feed the bacteria, which in turn fix nitrogen for the plants and assure them a steady supply of ammonia. Diana Gitig, Ars Technica, "Plants repeatedly got rid of their ability to obtain their own nitrogen," 27 May 2018 The Pacific’s mineral nodules were discovered by HMS Challenger, a British research vessel that first dredged the abyssal depths in the 1870s. The Economist, "Undersea miningRace to the bottom," 8 Mar. 2018 This treatment promotes the formation of root nodules, which contain beneficial bacteria that convert the nitrogen in the air into a form usable by plants. The Editors Of Organic Life, Good Housekeeping, "Growing Peas Has Never Been Easier Than This," 31 Mar. 2017 Last fall, Clauer was involved in a minor car accident; a precautionary CT scan revealed a nodule on her thyroid. Alec Johnson, Milwaukee Journal Sentinel, "Despite a lung defect and a cancer diagnosis, this Arrowhead senior is trying to make life better for others," 16 May 2018

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

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First Known Use of nodule

15th century, in the meaning defined above

History and Etymology for nodule

Middle English, from Latin nodulus, diminutive of nodus

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Statistics for nodule

Last Updated

10 Oct 2018

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Time Traveler for nodule

The first known use of nodule was in the 15th century

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More Definitions for nodule



English Language Learners Definition of nodule

: a small lump on a part of the body or on the root of a plant


nod·ule | \ˈnä-jül \

Kids Definition of nodule

: a small roundish lump or mass


nod·ule | \ˈnäj-(ˌ)ü(ə)l \

Medical Definition of nodule 

: a small mass of rounded or irregular shape: as

a : a small abnormal knobby bodily protuberance (as a tumorous growth or a calcification near an arthritic joint)

b : the nodulus of the cerebellum

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Comments on nodule

What made you want to look up nodule? Please tell us where you read or heard it (including the quote, if possible).


exaggeratedly or childishly emotional

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