1
a
: 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
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
T. B. Macaulay3
: 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
William Shakespeare2
: 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.
Recent Examples on the WebMaryal Miller Carter, USA TODAY, 4 Apr. 2024
The five blades are cloaked in aloe soap for a close, soothing shave, and the handle comes with a magnetic mount that sticks to the shower wall for easy access that fends off icky rust.
—Annie Blackman, Allure, 3 Apr. 2024
Sacramento health inspectors recently shut down a local restaurant and a hotel due to vermin infestation, improperly stored meat, rust, dust and other violations.
—Jacqueline Pinedo, Sacramento Bee, 3 Apr. 2024
In a recent study led by Australia's Royal Melbourne Institute of Technology, engineers coated battery parts with bismuth and rust, which protected against dendrites.
—Cameron Pugh, The Christian Science Monitor, 25 Mar. 2024
After the first-round loss to Oakland, rust is now apparent.
—Jon Wilner, The Mercury News, 25 Mar. 2024
Choose from nine colors, like rose red and rust, in sizes S–XXL.
—Jamie Allison Sanders, Peoplemag, 24 Mar. 2024
Store the cast iron pan in a dry place to prevent moisture from accumulating and causing rust.
—Maryal Miller Carter, USA TODAY, 21 Mar. 2024
In too-wet growing environments, diseases such as Botrytis blight (gray mold), root and stem rot, and rust are possible.
—Derek Carwood, Better Homes & Gardens, 18 Mar. 2024
Daley Quinn, Verywell Health, 1 Apr. 2024
Around the wall were rusting carcasses of helicopters and airplanes confiscated from miners on previous raids.
—Jon Lee Anderson, The New Yorker, 1 Apr. 2024
Better Homes & Gardens Rustproof Double Shower Curtain Hooks
$10
Water can quickly rust metal, which is why these rustproof shower curtain hooks are a must for your bathroom.
—Carly Totten, Better Homes & Gardens, 29 Mar. 2024
Do keep in mind that the handle is made from brass, which may rust over time.
—Isabella Ubaldi, Health, 20 Mar. 2024
Stewart recommends camellia oil, a Japanese oil extracted from the seed of a flowering shrub, to lubricate moving parts of tools and protect them from rusting with a preventative coating.
—Halee Miller, Better Homes & Gardens, 22 Mar. 2024
Offshoring turned thriving industrial centers to rust.
—TIME, 18 Mar. 2024
Stainless is reactive and free iron that sits on it will rust.
—Bryan Hood, Robb Report, 22 Feb. 2024
The blades are stainless steel and are designed not to rust, which is a bonus, because the grater is also dishwasher safe.
—Belle Duchene, Better Homes & Gardens, 8 Feb. 2024
Noun
If the zipper is stuck due to corrosion or rust, soaking a cotton swab in vinegar and gently rubbing it along the affected area can help loosen the corrosion and free the zipper.
—Maryal Miller Carter, USA TODAY, 4 Apr. 2024
The five blades are cloaked in aloe soap for a close, soothing shave, and the handle comes with a magnetic mount that sticks to the shower wall for easy access that fends off icky rust.
—Annie Blackman, Allure, 3 Apr. 2024
Sacramento health inspectors recently shut down a local restaurant and a hotel due to vermin infestation, improperly stored meat, rust, dust and other violations.
—Jacqueline Pinedo, Sacramento Bee, 3 Apr. 2024
In a recent study led by Australia's Royal Melbourne Institute of Technology, engineers coated battery parts with bismuth and rust, which protected against dendrites.
—Cameron Pugh, The Christian Science Monitor, 25 Mar. 2024
After the first-round loss to Oakland, rust is now apparent.
—Jon Wilner, The Mercury News, 25 Mar. 2024
Choose from nine colors, like rose red and rust, in sizes S–XXL.
—Jamie Allison Sanders, Peoplemag, 24 Mar. 2024
Store the cast iron pan in a dry place to prevent moisture from accumulating and causing rust.
—Maryal Miller Carter, USA TODAY, 21 Mar. 2024
In too-wet growing environments, diseases such as Botrytis blight (gray mold), root and stem rot, and rust are possible.
—Derek Carwood, Better Homes & Gardens, 18 Mar. 2024
Verb
Keep In Mind This tongue scraper seems to bend easily, and might also rust faster than a stainless steel option.
—Daley Quinn, Verywell Health, 1 Apr. 2024
Around the wall were rusting carcasses of helicopters and airplanes confiscated from miners on previous raids.
—Jon Lee Anderson, The New Yorker, 1 Apr. 2024
Better Homes & Gardens Rustproof Double Shower Curtain Hooks
$10
Water can quickly rust metal, which is why these rustproof shower curtain hooks are a must for your bathroom.
—Carly Totten, Better Homes & Gardens, 29 Mar. 2024
Do keep in mind that the handle is made from brass, which may rust over time.
—Isabella Ubaldi, Health, 20 Mar. 2024
Stewart recommends camellia oil, a Japanese oil extracted from the seed of a flowering shrub, to lubricate moving parts of tools and protect them from rusting with a preventative coating.
—Halee Miller, Better Homes & Gardens, 22 Mar. 2024
Offshoring turned thriving industrial centers to rust.
—TIME, 18 Mar. 2024
Stainless is reactive and free iron that sits on it will rust.
—Bryan Hood, Robb Report, 22 Feb. 2024
The blades are stainless steel and are designed not to rust, which is a bonus, because the grater is also dishwasher safe.
—Belle Duchene, Better Homes & Gardens, 8 Feb. 2024
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'rust.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Word History
First Known Use
Noun
before the 12th century, in the meaning defined at sense 1a
Verb
13th century, in the meaning defined at intransitive sense 1
Time Traveler
The first known use of rust was
before the 12th century
Phrases Containing rust
Dictionary Entries Near rust
Cite this Entry
“Rust.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rust. Accessed 16 Apr. 2024.
Copy Citation
Kids Definition
rust
1 of 2 noun1
: a reddish brittle coating formed on iron especially when chemically attacked by moist air and composed chiefly of ferric oxide
2
a
: any of numerous destructive diseases of plants caused by fungi and characterized by reddish brown spots
b
: any of an order of fungi that cause plant rusts
3
: a reddish brown
rust
2 of 2 verb
: to form or cause to form rust
iron rusts
Medical Definition
rust
noun1
: 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
More from Merriam-Webster on rust
Thesaurus: All synonyms and antonyms for rust
Nglish: Translation of rust for Spanish Speakers
Britannica English: Translation of rust for Arabic Speakers
Britannica.com: Encyclopedia article about rust
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