: 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
: 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
Kristine Gill, Better Homes & Gardens, 18 May 2026
For these reasons, safety precautions are paramount when using borax.
—Louise Parks, Martha Stewart, 17 May 2026
Homemade laundry detergent recipe without borax Borax is a divisive ingredient in green-cleaning circles.
—Ryan Brennan
may 13, Miami Herald, 13 May 2026
Utah State University Cooperative Extension publishes a similar version using two cups of grated soap, two cups of borax and two cups of washing soda, combined with two gallons of water.
—Ryan Brennan
may 13, Kansas City Star, 13 May 2026
See All Example Sentences for borax
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Noun
Ly suggests a mixture of half borax and half plain white sugar.
—Kristine Gill, Better Homes & Gardens, 18 May 2026
For these reasons, safety precautions are paramount when using borax.
—Louise Parks, Martha Stewart, 17 May 2026
Homemade laundry detergent recipe without borax Borax is a divisive ingredient in green-cleaning circles.
—Ryan Brennan
may 13, Miami Herald, 13 May 2026
Utah State University Cooperative Extension publishes a similar version using two cups of grated soap, two cups of borax and two cups of washing soda, combined with two gallons of water.
—Ryan Brennan
may 13, Kansas City Star, 13 May 2026
See All Example Sentences for borax
Cite this Entry
“Borax.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/borax. Accessed 23 May. 2026.
Copy CitationMedical Definition
borax
noun
bo·rax
ˈbō(ə)r-ˌaks 
ˈbȯ(ə)r-
ˈbȯ(ə)r-
-əks
: 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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