rust

noun
\ ˈrəst \

Definition of rust 

(Entry 1 of 2)

1a : the reddish brittle coating formed on iron especially when chemically attacked by moist air and composed essentially of hydrated ferric oxide

b : a comparable coating produced on a metal other than iron by corrosion

c : something resembling rust : accretion

2 : corrosive or injurious influence or effect

3 : any of numerous destructive diseases of plants produced by fungi (order Uredinales) and characterized by usually reddish-brown pustular lesions also : a fungus causing this

4 : a strong reddish brown

rust

verb
rusted; rusting; rusts

Definition of rust (Entry 2 of 2)

intransitive verb

1 : to form rust : become oxidized iron rusts

2 : to degenerate especially from inaction, lack of use, or passage of time most men would … have allowed their faculties to rust —T. B. Macaulay

3 : to become reddish brown as if with rust the leaves slowly rusted

4 : to be affected with a rust fungus

transitive verb

1 : to cause (a metal) to form rust keep up your bright swords, for the dew will rust them —William Shakespeare

2 : to impair or corrode by or as if by time, inactivity, or deleterious use

3 : to cause to become reddish brown : turn the color of rust

Examples of rust in a Sentence

Noun

an old pump covered in rust

Verb

Your bicycle will rust if you leave it out in the rain. The moist air rusted the latch on the door. The old iron fence was rusted.
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Recent Examples on the Web: Noun

The rust-orange stretch of rails and ties is known as Track 61. Adam Vaccaro, BostonGlobe.com, "How a South Boston real estate fight could delay new MBTA Red Line cars," 2 July 2018 Win a few matches, shake the rust off…I can definitely win this title. The Si Staff, SI.com, "French Open 2018 Preview Roundtable: Predictions, Dark Horses, More," 23 May 2018 The dented front half, on two flattened tires and with rust holes in the hood, sits just off old U.S. 56 at a defunct gas station. Eric Adler And Lynn Horsley, kansascity, "Eyesore or landmark? Debate roils in small Kansas town over decades-old half-car gag | The Kansas City Star," 24 Apr. 2018 With the hot weather though, the snapdragons will contract fungal rust disease and decline quickly. Calvin Finch, San Antonio Express-News, "What’s blooming in S.A. gardens now in April," 20 Apr. 2018 The backdrop was rust-red barns, and the clothes were a reflection of down-on-the-prairie Americana, with ruffled dresses, cowboy boots, farmer plaids, quilts, and crocheted knits. Emilia Petrarca, The Cut, "Calvin Klein’s Runway Was Covered With Truckloads of Popcorn," 13 Feb. 2018 It is highly inhibited against moisture and rusting in both fresh and sea water, passed both A and B Sequences of the ASTM D-665 turbine oil rust test and provides excellent water separation as shown in ASTM D-1401 demulsibility test. Andrew Joseph, For The Win, "Police are now greasing Philly light poles with hydraulic fluid to stop Eagles fans," 4 Feb. 2018 Keep an eye out—particularly in the Northwest—for carrot rust flies, which look like small green houseflies with yellow heads and red eyes. The Editors Of Organic Life, Good Housekeeping, "Everything You Need To Know To Grow Beautiful Carrots," 30 Aug. 2017 Excess water left on a cast iron leads to rust spots which will require cleaning and a fresh seasoning job. Esquire, "How to Care For a Cast Iron Skillet," 7 Dec. 2015

Recent Examples on the Web: Verb

The truck was rusted and appeared to have been in several wrecks. Jose R. Gonzalez, Houston Chronicle, "Louisiana authorities release facial reconstruction of severed head with similarities to HPD case," 27 June 2018 Inside was a collection of folded papers held together by disintegrating rubber bands and rusting staples. New York Times, "Found: Rosa Parks’s Arrest Warrant, and More Traces of Civil Rights History," 26 June 2018 But the pieces had sat out in the rain at the side of the highway for several days and had rusted. Meg Jones, Milwaukee Journal Sentinel, "Nightmare #1: Husband's death by flying debris on I-94. Nightmare #2: The investigation," 29 June 2018 Out front is one long unbroken run of rusting metal grates, beat-up signs, and decaying paint, while the area around back is littered with crushed beer cans, pillows, women’s lingerie, and signs of squatters. Alex Gailey, BostonGlobe.com, "Battered storefronts undermine progress at Dudley Square," 25 June 2018 There’s still rust on Serena’s game, the competition is quickly improving and, despite being a three-time champion of the event, the French Open has been her worst major. Chris Chase, For The Win, "Serena Williams has already won the French Open," 31 May 2018 Part of de-rusting yourself in the dating scene means going out of your comfort zone and trying experiences that are new and strange and maybe even terrifying. Anna Pulley, RedEye Chicago, "Ask Anna: Where do I meet single lesbians when I’m in my 40s?," 5 June 2017 Why: The awe-inspiring photo opportunities amid the rusted-saw peaks of the San Juan Mountains aren’t the only reason the 550 is called the Million Dollar Highway. latimes.com, "Detours worth taking on your next road trip," 20 May 2018 Officials have said the monument’s stone is shifting and its steel frame is rusting. Scott Huddleston, San Antonio Express-News, "Call sounded to keep Cenotaph in place," 17 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'rust.' 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 rust

Noun

before the 12th century, in the meaning defined at sense 1a

Verb

13th century, in the meaning defined at intransitive sense 1

History and Etymology for rust

Noun

Middle English, from Old English rūst; akin to Old English rēad red — more at red

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Statistics for rust

Last Updated

5 Sep 2018

Look-up Popularity

Time Traveler for rust

The first known use of rust was before the 12th century

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More Definitions for rust

rust

noun

English Language Learners Definition of rust

 (Entry 1 of 2)

: a reddish substance that forms on iron or some other metal usually when it comes in contact with moisture or air

: a disease that causes plants to develop reddish-brown spots

: a reddish-brown color

rust

verb

English Language Learners Definition of rust (Entry 2 of 2)

: to form rust : to become rusty

: to cause rust to form on (something)

rust

noun
\ ˈrəst \

Kids Definition of rust

 (Entry 1 of 2)

1 : a reddish coating formed on metal (as iron) when it is exposed especially to moist air

2 : a plant disease caused by fungi that makes spots on plants

3 : a fungus that causes a rust

rust

verb
rusted; rusting

Kids Definition of rust (Entry 2 of 2)

: to make or become rusty

rust

noun
\ ˈrəst \

Medical Definition of rust 

1 : the reddish brittle coating formed on iron especially when chemically attacked by moist air and composed essentially of hydrated ferric oxide

2 : any of numerous destructive diseases of plants produced by fungi (order Uredinales) and characterized by reddish brown pustular lesions also : a fungus causing this

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