- [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.
- An instrument or utensil made of iron; -- chiefly in composition; as, a flat iron, a smoothing iron, etc. "My young soldier, put up your iron." [Shak.]
- pl.Fetters; chains; handcuffs; manacles."Four of the sufferers were left to rot in irons." [Macaulay.]
- Strength; power; firmness; inflexibility; as, to rule with a rod of iron .
- [Golf] An iron-headed club with a deep face, chiefly used in making approaches, lifting a ball over hazards, etc.
Note: ☞ The value of iron is largely due to the facility with which it can be worked. Thus, when heated it is malleable and ductile, and can be easily welded and forged at a high temperature. As cast iron, it is easily fusible; as steel, is very tough, and (when tempered) very hard and elastic. Chemically, iron is grouped with cobalt and nickel. Steel is a variety of iron containing more carbon than wrought iron, but less that cast iron. It is made either from wrought iron, by roasting in a packing of carbon ( cementation) or from cast iron, by burning off the impurities in a Bessemer converter (then called Bessemer steel), or directly from the iron ore (as in the Siemens rotatory and generating furnace).
Etymology: OE. iren, AS. īren īsen īsern; akin to D. ijzer, OS. īsarn, OHG. īsarn īsan, G. eisen, Icel. īsarn jārn, Sw. & Dan. jern, and perh. to E. ice; cf. Ir. iarann, W. haiarn, Armor. houarn