\ ˈrəst How to pronounce rust (audio) \

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


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


an old pump covered in rust


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 hot, dry air of the southwestern desert prevents stored aircraft from developing rust or other corrosion issues. Kyle Mizokami, Popular Mechanics, "The Air Force Resurrects Another B-52 From the Boneyard," 15 May 2019 Born in Ireland, Mr. Roche made his career mostly in the U.S. and pioneered the use of indoor gardens, concealed parking spaces, reflective glass and steel alloys with rust-like patinas. James R. Hagerty, WSJ, "Kevin Roche Imagined Work Spaces to Make Office Life Livelier," 8 Mar. 2019 If Sunday's game was any indication, Detroit Tigers pitcher Francisco Liriano has a little more rust to knock off. Detroit Free Press, "Detroit Tigers Francisco Liriano struggles in rehab start for Toledo," 17 June 2018 Makeup artist Kelsey Deenihan gave the actor a glassy red-orange lip that could be seen for miles, and then used rust tones on her eyes to accompany the look. Kaleigh Fasanella, Allure, "Maisie Williams Wore a Full Face of Urban Decay’s Game of Thrones Makeup Collection to the Season 8 Premiere," 4 Apr. 2019 This rust-resistant brass version, $19.99, will look great years to come. Diane Cowen, Houston Chronicle, "10 things to love from Chip and Joanna Gaines new Hearth & Hand collection," 21 Jan. 2018 Here's the wildly glamorous evidence: James created a cobalt blue smokey eye with a rust orange cut crease, while Lauren's rocking a teal and purple eye with a mauve/maroon cut crease. Kelsey Stiegman, Seventeen, "James Charles Slams Accusations That He Copied Another Makeup Artist's Look," 20 June 2017 Usually American tour openers such as this one can be a bit clunky as a band shakes off the rust. Greg Kot,, "Radiohead keeps things volatile at United Center," 7 July 2018 If Porter can shake off the rust and coach Cuonzo Martin’s grinding defense can take hold, Missouri should advance. Usa Today Sports, USA TODAY, "2018 March Madness schedule: Friday's NCAA tournament times, TV guide, info," 16 Mar. 2018

Recent Examples on the Web: Verb

There’s diversity in the reason the inspector fired Stop Sales. Dented or rusted 6-pound cans of ketchup. David J. Neal, miamiherald, "Two-hundred rodent poops. Roaches in a microwave. Why these restaurants failed inspection," 4 June 2019 The national railway, like Ozymandias’ statue, rusted in the wilderness. Charles R. Morris, WSJ, "‘The Longest Line on the Map’ Review: The End of the Road," 8 Jan. 2019 Start at the stairs adjacent to the modern rusted-steel facade of the Gulch Crossing building on Demonbreun Street. Christian L. Wright, WSJ, "A Guide to Nashville’s Chicest New Neighborhood," 5 Mar. 2019 The basketball hoops had worn nets, and the swing set had rusted handles, with one of the seats detached. New York Times, "What Budget Cuts Mean for Third Graders in a Rural School," 5 June 2018 But after the disintegration of the USSR in 1991, Energia was left rusting in the hangars of Baikonur Cosmodrome in Kazakhstan. Anatoly Zak, Popular Mechanics, "Russia's New Rocket Project Might Resurrect a Soviet-Era Colossus," 24 July 2018 Stall dividers are hung from the ceiling rather than bolted to the floor—easier to clean the floor that way, and there isn’t hardware to rust on the floor. Scott Mccartney, WSJ, "Airports Try Stall Tactic: Better Bathrooms," 2 Jan. 2019 Parts of the roof have caved in, wooden panels are missing and the kitchen stoves have rusted. Lefteris Pitarakis, Fox News, "AP PHOTOS: Istanbul's historic orphanage awaits salvation," 9 Sep. 2018 Two state troopers were handcuffing two lanky, bedraggled guys and had them leaning over the side of their rusted out Dodge Aspen, while two German shepherds sniffed the vehicle. Anne Slowey, Condé Nast Traveler, "Fear and Self-Loathing in the American Southwest," 25 July 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


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


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

History and Etymology for rust


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

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Statistics for rust

Last Updated

30 May 2019

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



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



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

: to form rust : to become rusty
: to cause rust to form on (something)


\ ˈrəst How to pronounce rust (audio) \

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


rusted; rusting

Kids Definition of rust (Entry 2 of 2)

: to make or become rusty


\ ˈrəst How to pronounce rust (audio) \

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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More from Merriam-Webster on rust

Rhyming Dictionary: Words that rhyme with rust

Spanish Central: Translation of rust

Nglish: Translation of rust for Spanish Speakers

Britannica English: Translation of rust for Arabic Speakers Encyclopedia article about rust

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showing courage and determination

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