Definition of boron in US English:



  • The chemical element of atomic number 5, a nonmetallic solid.

    Boron is usually prepared as an amorphous brown powder, but when very pure it forms hard, shiny black crystals with semiconducting properties. The element has some specialized uses, such as in alloy steels and nuclear control rods

    • ‘They spray boron and energetic nitrogen atoms onto a clean, heated tungsten surface, held at 250 to 500 volts, in an ultrahigh vacuum.’
    • ‘Those with less than an octet are often called electron deficient and are typical of certain elements with an odd number of electrons, such as boron and nitrogen.’
    • ‘Nitrogen and boron are increasingly used in steels in small but significant concentrations.’
    • ‘Electrons from the n-type half are drawn to the p-type half because of the way that phosphorus and boron bond with silicon.’
    • ‘Zinc is in solid solution; boron, titanium and zirconium are seldom added in amounts sufficient to produce visible compounds.’
    • ‘Trace minerals that are already more than adequate in most diets include phosphorus, iodine, manganese, chloride, molybdenum and boron.’
    • ‘It was not until 1807, however, that Sir Humphrey Davy identified boron as a chemical element.’
    • ‘Nitrogen, phosphorus, potassium, sulphur and boron have been found to be important in Zambia.’
    • ‘The most widely used grain refiners are master alloys of titanium, or of titanium and boron, in aluminum.’
    • ‘The immobile nutrients are iron, sulfur, calcium, manganese, copper, zinc, boron, molybdenum, and chlorine.’
    • ‘The smaller element may be a nonmetallic element, such as boron, carbon, nitrogen, or silicon.’
    • ‘The mineral elements most likely to be deficient in vineyards are nitrogen, potassium, phosphorus, zinc, boron, iron, manganese, and magnesium.’
    • ‘Each layer is doped with tiny amounts of different impurities, usually phosphorus and boron.’
    • ‘In addition, soy also contains magnesium and boron, which are important co-factors of calcium for bone health.’
    • ‘This product is a laundry aid containing sodium, boron, oxygen, and water.’
    • ‘In certain cases, small metallic atoms, like boron and beryllium, may enter into restricted interstitial solid solutions.’
    • ‘Besides hydrogen and its isotope deuterium, researchers use the isotopes of boron, oxygen, nitrogen and carbon.’
    • ‘Diffusion methods modify the chemical composition of the surface with hardening species such as carbon, nitrogen, or boron.’
    • ‘Grain refinement by titanium, boron and zirconium additions has only a limited effect on mechanical properties.’
    • ‘These rare coloured stones are highly treasured; their coloration comes from traces of elements such as boron and nitrogen or from structural flaws in the crystal lattice.’


Early 19th century: from borax, on the pattern of carbon (which it resembles in some respects).