brown rat

noun

Definition of brown rat 

: a common domestic rat (Rattus norvegicus) that has been introduced worldwide

called also Norway rat

Examples of brown rat in a Sentence

Recent Examples on the Web

Black rats weigh in at 41/2 ounces and grow up to 5 to 6 inches long; adult brown rats weigh 9 to 10 ounces and reach up to 16 inches. Kym Pokorny, OregonLive.com, "'It's a bad year for rats' in Oregon cities: Here's how to fight them," 13 Feb. 2018 In our study, the commonest wild animal detected in New York City waters was the brown rat, a common urban denizen. Mark Stoeckle, Smithsonian, "Scientists Can Tell What Fish Live Where Based On DNA in the Water," 13 Apr. 2017

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

First Known Use of brown rat

1737, in the meaning defined above

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The first known use of brown rat was in 1737

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More Definitions for brown rat

brown rat

noun

Medical Definition of brown rat 

: a common domestic rat of the genus Rattus (R. norvegicus) that has been introduced worldwide

called also Norway rat

More from Merriam-Webster on brown rat

See words that rhyme with brown rat

Britannica.com: Encyclopedia article about brown rat

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