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\ 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
verbrusted; rusting; rusts
Definition of rust (Entry 2 of 2)
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
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 Even while shaking off the rust in his first practice since 2015, the combination of his movement ability and size is daunting.
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Michael Gehlken, Dallas News, "Cowboys training camp observations: CeeDee Lamb already wowing; Donovan Wilson just makes plays," 14 Aug. 2020 Turning rust into a useful chemical source material is cost-effective and demonstrates how inert materials hold the potential to be transformative in chemical manufacturing.
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Julio M. D'arcy, The Conversation, "Clever chemistry turns ordinary bricks into electricity storage devices," 11 Aug. 2020 Remove bedding in dark colors like rust, navy, charcoal and brown, and replace it with a lighter palette of breezy pastels and white.
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Marni Jameson, orlandosentinel.com, "How to make a cool bed in hot weather," 7 Aug. 2020 Seasoning makes the pan easy to clean, prevents rust, and keeps food from sticking.
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Joseph Truini, Popular Mechanics, "How To Clean a Cast-Iron Pan," 27 June 2020 Then, a small team of part-time mechanics—consisting of Mark and a few buddies—strips them down, rebuilds the major mechanical components, and removes any rust.
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Talon Homer, Car and Driver, "The Cars Are the Stars: The Art of Replicating Hollywood's Famous Rides," 14 June 2020 The steel used to build the bridge was prone to oxidation and needed to be sandblasted to remove rust before installation.
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David Kindy, Smithsonian Magazine, "The History of the Hard Hat," 21 Feb. 2020 Clean the shears before sharpening, and be sure to remove any rust as well.
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Anthony Marcusa, chicagotribune.com, "The best long-handle grass shear," 4 Aug. 2020 Despite nearly five months between games – 142 days, to be exact – the Mavericks’ NBA-best offense showed little rust Friday night.
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Dallas News, "Mavericks ‘played their butts off’, but late-game woes continued in a tough loss vs. Houston," 1 Aug. 2020 Recent Examples on the Web: Verb Having fasteners rust away is clearly a safety hazard on a structure such as a deck.
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Jeanne Huber, Washington Post, "Is wood still a viable option for retaining walls, or will it deteriorate quickly?," 17 Aug. 2020 The whisk itself is made with a 316 surgical-grade stainless-steel that’s designed to remain in the bottle during use and never rust, chip or peel.
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Nicole Briese, USA TODAY, "The 5 best Amazon deals you can get this weekend," 8 Aug. 2020 In 1961, the road was completed and the company abandoned the bus, leaving it to rust away along the Stampede Trail.
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Alex Fox, Smithsonian Magazine, "‘Into the Wild’ Bus Airlifted Out of the Wilderness," 24 June 2020 That’s because if it’s not properly maintained and seasoned, cast iron will rust and food will stick.
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Joseph Truini, Popular Mechanics, "How To Clean a Cast-Iron Pan," 27 June 2020 Copper cutters are durable, hold their shape well and won’t rust.
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NBC News, "Best cookie cutters and where to buy them, according to experts," 15 June 2020 Given that college teams played about two week’s worth of games this year, that’s one thing scouts can be sure didn’t rust in the COVID-19 lockdown.
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Dallas News, "How MLB’s uncertain future may help explain the Rangers’ selection of Mississippi State 2B Justin Foscue," 11 June 2020 Over time, the metal can rust and cause the secondary latch to stay open.
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Tom Krisher, Detroit Free Press, "Nissan recalls nearly 1.9M cars for pesky hood latch problem," 4 June 2020 Now many of those cars are rusting in a west-side tow yard.
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Amelia Pak-harvey, Indianapolis Star, "As BlueIndy cars pile up in junkyard, city seeks ideas for old charging spots, parking," 29 May 2020
See MoreThese 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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More Definitions for rust
rust
nounEnglish 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
verbEnglish Language Learners Definition of rust (Entry 2 of 2)
: to form rust : to become rusty
: to cause rust to form on (something)
See the full definition for rust in the English Language Learners Dictionary
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
verbrusted; 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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Time Traveler for rust
The first known use of rust was before the 12th century
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