from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A silvery-white, lustrous, malleable, ductile, magnetic or magnetizable, metallic element occurring abundantly in combined forms, notably in hematite, limonite, magnetite, and taconite, and used alloyed in a wide range of important structural materials. Atomic number 26; atomic weight 55.845; melting point 1,538°C; boiling point 2,861°C; specific gravity 7.874 (at 20°C); valence 2, 3, 4, 6. cross-reference: Periodic Table.
  • noun An implement made of iron alloy or similar metal, especially a bar heated for use in branding, curling hair, or cauterizing.
  • noun Great hardness or strength; firmness.
  • noun Sports Any of a series of golf clubs having a bladelike metal head and numbered from one to nine in order of increasing loft.
  • noun A metal appliance with a handle and a weighted flat bottom, used when heated to press wrinkles from fabric.
  • noun A harpoon.
  • noun Fetters; shackles.
  • noun A tonic, pill, or other medication containing iron and taken as a dietary supplement.
  • adjective Made of or containing iron.
  • adjective Strong, healthy, and capable of great endurance.
  • adjective Inflexible; unyielding.
  • adjective Holding tightly; very firm.
  • intransitive verb To press and smooth with a heated iron.
  • intransitive verb To remove (creases) by pressing.
  • intransitive verb To put into irons; fetter.
  • intransitive verb To fit or clad with iron.
  • intransitive verb To iron clothes.
  • idiom (in irons) Lying head to the wind and unable to turn either way.
  • idiom (iron in the fire) An undertaking or project in progress.

from The Century Dictionary.

  • To shackle with irons; fetter; handcuff.
  • To furnish, mount, or arm with iron: as, to iron a wagon.
  • To smooth with an instrument of iron, especially with a hot flat-iron, smoothing-iron, or box-iron.
  • noun Chemical symbol, Fe; atomic weight, 56. A metal, the most abundant and the most important of all those used in the metallic form.
  • noun A utensil or weapon made of iron: often in combination with a noun or an adjective expressive of its purpose or character : as, a flat-iron, gridiron, or shooting-iron (slang for pistol).
  • noun Specifically— A knife, sword, or other cutting implement.
  • noun plural Fetters or other chains fastened to the person of a prisoner: as, a mutineer is put in irons.
  • noun In whaling, a hand-harpoon; a toggle-iron, used in striking a whale. There are two forms, the first and second irons (which see, below).
  • noun A brand-iron.
  • noun To have, as a square-rigged vessel, the yards so braced that, some sails being full of wind and some aback, the vessel is temporarily unmanageable.
  • Made of iron; consisting of iron: as, an iron gate; an iron bar.
  • Resembling iron in some respect, either really or metaphorically.
  • Hence— Harsh; rude; severe.
  • Binding fast ; not to be broken.
  • Capable of great endurance; firm; robust: as, an iron constitution.
  • Not to be bent; inflexible.
  • In mining, same as gossan. [U.S.]

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Chem.) The most common and most useful metallic element, being of almost universal occurrence, usually in the form of an oxide (as hematite, magnetite, etc.), or a hydrous oxide (as limonite, turgite, etc.). It is reduced on an enormous scale in three principal forms; viz., cast iron, steel, and wrought iron. Iron usually appears dark brown, from oxidation or impurity, but when pure, or on a fresh surface, is a gray or white metal. It is easily oxidized (rusted) by moisture, and is attacked by many corrosive agents. Symbol Fe (Latin Ferrum). Atomic number 26, atomic weight 55.847. Specific gravity, pure iron, 7.86; cast iron, 7.1. In magnetic properties, it is superior to all other substances.
  • noun An instrument or utensil made of iron; -- chiefly in composition
  • noun Fetters; chains; handcuffs; manacles.
  • noun Strength; power; firmness; inflexibility.
  • noun (Golf) An iron-headed club with a deep face, chiefly used in making approaches, lifting a ball over hazards, etc.
  • noun See Wrought iron (below).
  • noun bog ore; limonite. See Bog ore, under Bog.
  • noun (Metal.) an impure variety of iron, containing from three to six percent of carbon, part of which is united with a part of the iron, as a carbide, and the rest is uncombined, as graphite. It there is little free carbon, the product is white iron; if much of the carbon has separated as graphite, it is called gray iron. See also Cast iron, in the Vocabulary.
  • noun See under Fire, n.
  • noun See under Fire, n.
  • noun See Cast iron (above).


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English iren, from Old English īren; see eis- in Indo-European roots.]


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  • Can be spelled with the Periodic Table of Elements symbols: IrON

    December 12, 2006

  • A traditional unit of measure for the thickness of leather used in making shoes, especially soles. One iron is equal to 1/48 inch (0.5292 millimeter), so a sole that's 1/4-inch thick is described as "12 iron."

    November 6, 2007

  • Fe.

    December 16, 2007

  • There's a conversaton on this list about the pronunciation of this word. Since that long-ago time, I found out that "i-ern" is a quite common pronunciation in the United States, while "i-ron" is more common in the U.K. (don't know where else, perhaps Australia?).

    Just thought I'd mention it. Don't have the book with me so I can't cite it here just yet, but I will if anyone's interested.

    October 10, 2008

  • No iron tool of any kind was employed in the building of the Temple in order that quiet and reverence might prevail.

    (Source: Masonic dictionary)

    November 17, 2008

  • "iron" in Hungarian means: pencil (especially the one used by carpenters)

    August 7, 2012