borax
1 Americannoun
noun
noun
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Also called: tincal. a soluble readily fusible white mineral consisting of impure hydrated disodium tetraborate in monoclinic crystalline form, occurring in alkaline soils and salt deposits. Formula: Na 2 B 4 O 7 .10H 2 O
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pure disodium tetraborate
Other Word Forms
Noun Inflected Forms
Etymology
Origin of borax1
1350–1400; < Medieval Latin ≪ dialectal Arabic būraq < Middle Persian būrag; replacing Middle English boras < Middle French < Medieval Latin borax
Origin of borax2
An Americanism dating back to 1940–45; of uncertain origin
Explanation
Borax is a mineral that's often used in a powdered form as a cleanser or water softener. Borax is another name for sodium borate, a chemical salt that was discovered in 8th-century Tibet. Medieval ceramicists used borax in their pottery glazes, and in modern times it's been used to make glass. Borax can also act as a fire retardant in wood and textiles. In household use, borax is still sometimes added to a load of laundry or worked into soil as a fertilizer. It is widely attested that the name borax comes from the Persian word būrah.
Vocabulary lists containing borax
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
A borax man seems a finer, near-perfect fit.
From The Wall Street Journal • Dec. 18, 2025
Not every trend on TikTok is as horrific or annoying as drinking borax or pranking strangers — some memes are downright heartwarming.
From Salon • Jun. 1, 2024
The fire, one of two that day, occurred just after midnight April 4 behind the Borax Museum and destroyed a wooden wagon used to transport borax out of Death Valley in the late 1800s.
From Los Angeles Times • May 15, 2024
You can create a natural cleaning solution from baking soda, lemon juice and borax.
From Seattle Times • Feb. 20, 2024
I’ve got glue, Mom’s baking soda, a four-pound box of borax, and several vials of food coloring.
From "Blended" by Sharon M. Draper
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.