borax

1 of 2

noun (1)

bo·​rax ˈbȯr-ˌaks How to pronounce borax (audio) -əks How to pronounce borax (audio)
: a white crystalline compound that consists of a hydrated sodium borate Na2B4O7·10H2O, that occurs as a mineral or is prepared from other minerals, and that is used especially as a flux, cleansing agent, and water softener, as a preservative, and as a fireproofing agent

borax

2 of 2

noun (2)

: cheap shoddy merchandise

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What are the Uses of borax?

A borate of sodium that occurs as a soft, light, colorless crystalline mineral, borax has a wide variety of uses. It can be used as a component of glass and pottery glazes in the ceramics industry, as a solvent in metallurgy, as a flux in welding and soldering, and as a fertilizer additive, a soap supplement, a disinfectant, a mouthwash, and a water softener. About 50 percent of the world’s supply comes from southern Californian deserts, including Death Valley.

Examples of borax in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
Borax Bait: Combine borax with sugar to attract and kill ants. Mary Marlowe Leverette, Southern Living, 25 May 2025 Ly suggests a mix of half borax and half plain white sugar. Kristine Gill, Better Homes & Gardens, 27 June 2024 The group worked their way through borax, boric acid, salicylic acid, benzoic acid, sulfur dioxide, formaldehyde, copper sulfate, and saltpeter– among other things. Lauren Leffer, Popular Science, 1 May 2025 These hydrogels were made of a polymer net that gave them their shape, crosslinkers like borax or hydrogen bonds that held this net together, a liquid phase made of water, and salt or other electrolyte additives providing ions that moved through the watery gel as the battery charged or discharged. ArsTechnica, 14 Apr. 2025 See All Example Sentences for borax

Word History

Etymology

Noun (1)

Middle English boras, from Anglo-French boreis, from Medieval Latin borac-, borax, from Arabic būraq, from Persian būrah

Noun (2)

origin unknown

First Known Use

Noun (1)

14th century, in the meaning defined above

Noun (2)

1932, in the meaning defined above

Time Traveler
The first known use of borax was in the 14th century

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Cite this Entry

“Borax.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/borax. Accessed 13 Jun. 2025.

Kids Definition

borax

noun
bo·​rax
ˈbō(ə)r-ˌaks,
ˈbȯ(ə)r-
: a borate of sodium that occurs as a mineral and is used in agricultural chemicals, as a cleansing agent, and as a water softener

Medical Definition

borax

noun
: a white crystalline compound that consists of a hydrated sodium borate Na2B4O7·10H2O, that occurs as a mineral or is prepared from other minerals, and that is used especially as a flux, cleansing agent, and water softener and as a preservative

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