noun

• (uncountable) A common, inexpensive metal, silvery grey when untarnished, that rusts, is attracted by magnets, and is used in making steel: a chemical element having atomic number 26 and symbol Fe.
  "He studied about rocks including iron in school."
• (uncountable, countable, metallurgy) Any material, not a steel, predominantly made of elemental iron.
• (countable) A tool or appliance made of metal, which is heated and then used to transfer heat to something else; most often a thick piece of metal fitted with a handle and having a flat, roughly triangular bottom, which is heated and used to press wrinkles from clothing, and now usually containing an electrical heating apparatus.
• (usually in the plural, irons) Shackles.

adj

• (not comparable) Made of the metal iron.
• (figuratively) Strong (as of will), inflexible.
  "She had an iron will."

verb

• (transitive) To pass an iron over (clothing or some other item made of cloth) in order to remove creases.
  "You'd be wise to iron that shirt before you wear it."
• (intransitive) To engage in such pressing of clothing.
  "They were washing and ironing all morning."
• (transitive, archaic) To shackle with irons; to fetter or handcuff.
  "[...] is it he who is ironed like a malefactor—who is to be dragged on a hurdle to the common gallows—to die a lingering and cruel death, and to be mangled by the hand of the most outcast of wretches?"
• (transitive) To furnish, clad, or arm with iron.
  "to iron a wagon"