rust

1 of 2

noun

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

rust

2 of 2

verb

rusted; rusting; rusts

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 rustT. 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 themWilliam 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.
Recent Examples on the Web
Noun
The material resists rust and rot, unlike metal or wood. Clara McMahon, Peoplemag, 27 Sep. 2024 Doing so protects it from rust, moisture, and general wear and tear. Michelle Ullman, Better Homes & Gardens, 26 Sep. 2024
Verb
When the service was retired in 1986, the beautiful cars were left to rust in a warehouse. Charlie Hobbs, Condé Nast Traveler, 25 Sep. 2024 The glass balustrades have been replaced with safety barriers that already have rusted. Martha Ross, The Mercury News, 11 June 2024 See all Example Sentences for rust 

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

Etymology

Noun

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

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

Dictionary Entries Near rust

Cite this Entry

“Rust.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rust. Accessed 7 Oct. 2024.

Kids Definition

rust

1 of 2 noun
1
: 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

noun
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
Last Updated: - Updated example sentences
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