\ ˈī(-ə)rn \

Definition of iron 

(Entry 1 of 3)

1 : a silver-white malleable ductile magnetic heavy metallic element that readily rusts in moist air, occurs native in meteorites and combined in most igneous rocks, is the most used of metals, and is vital to biological processes — see Chemical Elements Table

2 : something made of iron: such as

a : a household device usually with a flat metal base that is heated to smooth, finish, or press (such as cloth)

b : any of a series of numbered golf clubs having relatively thin metal heads — compare wood

c irons plural : shackles for the hands or legs

d : a heated metal implement used for branding or cauterizing

e : stirrup usually used in plural

3 : great strength, hardness, or determination

iron in the fire

1 : a matter requiring close attention

2 : a prospective course of action



Definition of iron (Entry 2 of 3)

1 : of, relating to, or made of iron

2 : resembling iron

3a : strong and healthy : robust an iron constitution

b : inflexible, unrelenting iron determination

c : holding or binding fast an iron grip


ironed; ironing; irons

Definition of iron (Entry 3 of 3)

transitive verb

1a : to smooth with or as if with a heated iron iron a shirt

b : to remove (something, such as wrinkles) by ironing

2 : to shackle with irons

3 : to furnish or cover with iron

intransitive verb

: to smooth or press cloth or clothing with a heated iron

Keep scrolling for more

Other words from iron


ironness \ˈī(-ə)rn-nəs \ noun

Synonyms & Antonyms for iron

Synonyms: Adjective

firm, forceful, hearty, lusty, robust, solid, stout, strong, sturdy, vigorous

Antonyms: Adjective

uncertain, weak

Visit the Thesaurus for More 

Examples of iron in a Sentence


he had an iron determination to succeed in on Wall Street

Recent Examples on the Web: Noun

An Elgin man who beat a man and woman with a clothes iron, computer monitor and wooden chair was sentenced to 28 years in prison Wednesday by Kane County Circuit Judge Clint Hull. Staff Report, Elgin Courier-News, "Elgin man gets 28 years for beating that left victims with broken teeth, permanent scars," 12 July 2018 Jindal Steel & Power, the Indian steelmaker controlled by billionaire Savitri Jindal’s family, manufactures sponge iron, mild steel, and cement. Paul Burkhardt,, "Jindal Steel South Africa Units File for Business Protection," 26 June 2018 Most associate football workouts with players pumping iron or doing sprints to boost their speed and strength. Drew Davison, star-telegram, "Yoga? Cowboys' Jaylon Smith explains how his new offseason routine is paying off," 31 May 2018 The results have caused both excitement and controversy in the medical community, where enthusiasm for the bone-building benefits of pumping iron has long been tempered by safety concerns. Laura Johannes, WSJ, "The Common Advice for Those With Thinning Bones Could Be All Wrong," 22 Apr. 2018 After growing up in the small Austrian village of Thal, where his father was the chief of police, Schwarzenegger began pumping iron in his local gym and went on to win the Junior Mr. Europe Contest in 1965. Sam Dangremond, Town & Country, "How Much Is Arnold Schwarzenegger Worth?," 30 Mar. 2018 Staying active as you age doesn’t mean just pumping iron or doing calisthenics anymore. Julie Landry Laviolette, miamiherald, "Do a dance. Play in the pool. Here’s how to keep fit as you age. | Miami Herald," 26 Mar. 2018 Tennessee rushed down court and got a decent look at a 3-pointer, but the Vols' last shot hit the back iron and Loyola was into the Sweet Sixteen. Dan Mann And Jonathon Berlin,, "Cinderella shots: Loyola's three epic NCAA buzzer-beaters," 23 Mar. 2018 Sackett is a big man, with lots of irons in the fire. Carl Nolte,, "At the Box SF, previous eras’ castoffs prove valuable today," 8 July 2018

Recent Examples on the Web: Verb

Then, use transfer paper to iron the Starbucks logo onto your dress. Elizabeth Denton, Seventeen, "14 Genius Group Halloween Costume Ideas for You and Your Squad," 6 July 2018 After the wet strips were pulled from the water, they were rushed to a nearby laundromat to be dried, then hauled back up to be ironed and sewn. Hailey Branson-potts,, "On the 40th anniversary of the LGBTQ pride symbol, artist wants her rainbow flag story told," 8 June 2018 As of Tuesday, the Diamondbacks had signed most of their top picks but still needed to iron things out with first-round selection Matt McLain, a high school infielder from California. Steve Reaven,, "Tyler Acosta, godson of Vladimir Guerrero, deciding between pro and college baseball," 19 June 2018 Training camp will come and things will iron themselves out. Andrew Hussey, Indianapolis Star, "Finally on a winner, Kyle O'Quinn embraces new chance with Pacers," 9 July 2018 Rows of workers are silently hunched over chattering sewing machines, others are ironing or stitching buttons. The Economist, "Culture and the labour market keep India’s women at home," 5 July 2018 After filling open-ended tea bags made of conventional filter paper, students will add a string to the bag and then iron the opening closed. Ginger Brashinger, Daily Southtown, "Learn how to grow, pick and blend your own tea herbs during Palos Park workshop," 27 June 2018 If there's white cotton curtains in the house, bleaching and starching them while ironing are efforts that go a long way. 6. Melissa Rolland,, "Projects That Don't Break The Bank," 19 June 2018 On ironing more strategically—and avoiding the clothes dryer My mother was an amazing homemaker. Carmen Rosy Hall, Vogue, "How Set Designer Noemi Bonazzi Cultivates Effortless Italian Style," 25 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'iron.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of iron


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


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


15th century, in the meaning defined at transitive sense 3

History and Etymology for iron


Middle English, from Old English īsern, īren; akin to Old High German īsarn iron

Keep scrolling for more

Learn More about iron

Dictionary Entries near iron





Iron Age

iron alum


Statistics for iron

Last Updated

6 Sep 2018

Look-up Popularity

Time Traveler for iron

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

See more words from the same century

Keep scrolling for more

More Definitions for iron



English Language Learners Definition of iron

 (Entry 1 of 3)

: a heavy type of metal that is very common, occurs naturally in blood, and is used to make steel and in many products

: a device with a flat metal base that is heated and is used to press wrinkles out of clothing

: a golf club that has a metal head and is identified by a number



English Language Learners Definition of iron (Entry 2 of 3)

: made of iron

: very strong



English Language Learners Definition of iron (Entry 3 of 3)

: to use a heated iron to make clothing or fabric smooth


\ ˈī-ərn \

Kids Definition of iron

 (Entry 1 of 3)

1 : a heavy silvery white metallic chemical element that rusts easily, is strongly attracted by magnets, occurs in meteorites and combined in minerals, and is necessary for transporting oxygen in the blood

2 : a device that is heated and used for making cloth smooth

3 : a device that is heated to perform a task a soldering iron

4 irons plural : handcuffs or chains used to bind or to hinder movement



Kids Definition of iron (Entry 2 of 3)

1 : made of iron

2 : strong and healthy He has an iron constitution.

3 : not giving in an iron will


ironed; ironing

Kids Definition of iron (Entry 3 of 3)

: to press with a heated iron


\ ˈī(-ə)rn \

Medical Definition of iron 

1 : a heavy malleable ductile magnetic silver-white metallic element that readily rusts in moist air, occurs native in meteorites and combined in most igneous rocks, is the most used of metals, and is vital to biological processes (as in transport of oxygen in the body) symbol Fe — see Chemical Elements Table

2 : iron chemically combined iron in the blood

Other words from iron

iron adjective

Keep scrolling for more

More from Merriam-Webster on iron

Thesaurus: All synonyms and antonyms for iron

Spanish Central: Translation of iron

Nglish: Translation of iron for Spanish Speakers

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

Comments on iron

What made you want to look up iron? Please tell us where you read or heard it (including the quote, if possible).


to make amends

Get Word of the Day daily email!

Test Your Vocabulary

Musical Words Quiz

  • gramophone
  • Which word describes a musical performance marked by the absence of instrumental accompaniment?
Spell It

Can you spell these 10 commonly misspelled words?

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!