iron vs surd

iron

noun
  • A metallic chemical element having atomic number 26 and symbol Fe. 

  • A common, inexpensive metal, silvery grey when untarnished, that rusts, is attracted by magnets, and is used in making steel. 

  • A golf club used for middle-distance shots. 

  • Any material, not a steel, predominantly made of elemental iron. 

  • A dark shade of the color silver. 

  • 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. 

  • shackles. 

  • A male homosexual. 

  • Used as a symbol of great strength or toughness, or to signify a very strong or tough material. 

  • A meteorite consisting primarily of metallic iron (mixed with a small amount of nickel), as opposed to one composed mainly of stony material. 

  • A safety curtain in a theatre. 

  • dumb bombs, those without guidance systems. 

  • Weight used as resistance for the purpose of strength training. 

  • A firearm, either a long gun or a handgun. 

adj
  • Made of the metal iron. 

  • Strong (as of will), inflexible. 

verb
  • To pass an iron over (clothing or some other item made of cloth) in order to remove creases. 

  • To furnish or arm with iron. 

surd

noun
  • An irrational number, especially one expressed using the √ symbol. 

  • A voiceless consonant. 

adj
  • unvoiced; voiceless 

  • Involving surds, or irrational numbers; not capable of being expressed in rational numbers. 

How often have the words iron and surd occurred in a corpus of books? (source: Google Ngram Viewer )