boron

American  

[bawr-on, bohr-] / ˈbɔr ɒn, ˈboʊr- /

noun

Chemistry.

1. a nonmetallic element occurring naturally only in combination, as in borax or boric acid, and obtained in either an amorphous or a crystalline form when reduced from its compounds. B; 10.811; 5.

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boron British  

/ ˈbɔːrɒn /

noun

1. a very hard almost colourless crystalline metalloid element that in impure form exists as a brown amorphous powder. It occurs principally in borax and is used in hardening steel. The naturally occurring isotope boron-10 is used in nuclear control rods and neutron detection instruments. Symbol: B; atomic no: 5; atomic wt: 10.81; valency: 3; relative density: 2.34 (crystalline), 2.37 (amorphous); melting pt: 2092°C; boiling pt: 4002°C

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boron Scientific  

/ bôr′ŏn′ /

1. A shiny, brittle, black metalloid element extracted chiefly from borax. It is a good electrical conductor at high temperatures and a poor conductor at low temperatures. Boron is necessary for the growth of land plants and is used in the preparation of soaps, abrasives, and hard alloys. It is also used in the control rods of nuclear reactors as a neutron absorber. Atomic number 5; atomic weight 10.811; melting point 2,300°C; sublimation point 2,550°C; specific gravity (crystal) 2.34; valence 3.

2. See Periodic Table

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Other Word Forms

• boronic adjective

Etymology

Origin of boron

1805–15; bor(ax ¹ ) + (carb)on

Example Sentences

In the future it will fuse hydrogen and boron to create clean energy.

From The Wall Street Journal • Mar. 28, 2026

In the future it will fuse hydrogen and boron to create clean energy.

From The Wall Street Journal • Mar. 28, 2026

Yet, once he and Grace work out their kinks and get to know each other, the Eridian reveals his own goofy personality — imagine a hybrid of boron and Borat.

From Los Angeles Times • Mar. 18, 2026

Finally Ioneer benefits from executive orders mandating increased domestic production of boron.

From Barron's • Nov. 17, 2025

The result of their bombardments of boron and other light elements by alpha rays, moreover, had led them to propose that the proton was composed of a neutron and a positive electron, or positron.

From "Big Science" by Michael Hiltzik