3. Like iron in hardness, strength, impenetrability, power of
endurance, insensibility, etc.; as:
(a) Rude; hard; harsh; severe.
Iron years of wars and dangers.
Rowe.
Jove crushed the nations with an iron rod.
Pope.
(b) Firm; robust; enduring; as, an iron constitution.
(c) Inflexible; unrelenting; as, an iron will.
(d) Not to be broken; holding or binding fast; tenacious. "Him death's
iron sleep oppressed." Philips.
Iron is often used in composition, denoting made of iron, relating to
iron, of or with iron; producing iron, etc.; resembling iron, literally
or figuratively, in some of its properties or characteristics; as,
iron-shod, iron-sheathed, iron-fisted, iron-framed, iron-handed,
iron-hearted, iron foundry or iron-foundry.
Iron age. (a) (Myth.) The age following the golden, silver, and bronze
ages, and characterized by a general degeneration of talent and virtue,
and of literary excellence. In Roman literature the Iron Age is
commonly regarded as beginning after the taking of Rome by the Goths,
A. D. 410. (b) (Archæol.) That stage in the development of any people
characterized by the use of iron implements in the place of the more
cumbrous stone and bronze. -- Iron cement, a cement for joints,
composed of cast-iron borings or filings, sal ammoniac, etc. -- Iron
clay (Min.), a yellowish clay containing a large proportion of an ore
of iron. -- Iron cross, a Prussian order of military merit; also, the
decoration of the order. -- Iron crown, a golden crown set with jewels,
belonging originally to the Lombard kings, and indicating the dominion
of Italy. It was so called from containing a circle said to have been
forged from one of the nails in the cross of Christ. -- Iron flint
(Min.), an opaque, flintlike, ferruginous variety of quartz. -- Iron
founder, a maker of iron castings. -- Iron foundry, the place where
iron castings are made. - - Iron furnace, a furnace for reducing iron
from the ore, or for melting iron for castings, etc.; a forge; a
reverberatory; a bloomery. -- Iron glance (Min.), hematite. -- Iron
hat, a headpiece of iron or steel, shaped like a hat with a broad brim,
and used as armor during the Middle Ages. -- Iron horse, a locomotive
engine. [Colloq.] -- Iron liquor, a solution of an iron salt, used as a
mordant by dyers. -- Iron man (Cotton Manuf.), a name for the
self-acting spinning mule. -- Iron mold or mould, a yellow spot on
cloth stained by rusty iron. -- Iron ore (Min.), any native compound of
iron from which the metal may be profitably extracted. The principal
ores are magnetite, hematite, siderite, limonite, Göthite, turgite, and
the bog and clay iron ores. -- Iron pyrites (Min.), common pyrites, or
pyrite. See Pyrites. -- Iron sand, an iron ore in grains, usually the
magnetic iron ore, formerly used to sand paper after writing. -- Iron
scale, the thin film which forms on the surface of wrought iron in the
process of forging. It consists essentially of the magnetic oxide of
iron, Fe3O4. -- Iron works, a furnace where iron is smelted, or a
forge, rolling mill, or foundry, where it is made into heavy work, such
as shafting, rails, cannon, merchant bar, etc.