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lye

American  
[lahy] / laɪ /

noun

Chemistry.
lyes plural
  1. a highly concentrated, aqueous solution of potassium hydroxide or sodium hydroxide.

  2. any solution resulting from leaching, percolation, or the like.


lye British  
/ laɪ /

noun

  1. any solution obtained by leaching, such as the caustic solution obtained by leaching wood ash

  2. a concentrated solution of sodium hydroxide or potassium hydroxide

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

lye Scientific  
/ lī /
  1. A strong alkaline solution or solid of potassium hydroxide or sodium hydroxide, made by allowing water to wash through wood ashes. It is used to make soap and drain and oven cleaners. Chemical formula: KOH or NaOH.


Other Word Forms

Noun Inflected Forms

Etymology

Origin of lye

First recorded before 900; Middle English lie, ley, Old English lēag; cognate with Dutch loog, German Lauge “lye,” Old Norse laug “warm bath”; see lave 1

Explanation

Lye is an alkaline solution that's used for cleaning. If you were a maid about 200 years ago, you probably cleaned the chamber pots with lye. Lye is an old cleaning product and an old word too. It comes from the Old English léag, which is related to the root for "wash" in our word lather. Lye is still used to make soap, but you probably won't come across the word except in old novels. If you become a historical re-enactor, say goodbye to body wash and hello to lye.

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Vocabulary lists containing lye

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.

Ed Lye, also from Penmaenmawr, said he was unhappy because it was the third year in a row he saw a large increase.

From BBC • Apr. 7, 2025

Lye, a former PGA Tour golfer, alleges that he was told that he couldn’t appear on the Saturday night show and was fired on Sunday morning.

From Washington Times • Feb. 9, 2022

Who knew That the smallest of bases Could make a Big Lye!

From Washington Post • Oct. 14, 2021

She fired the ball to catcher Aubree Munro, who tagged pinch-runner Joey Lye out at the plate.

From Fox News • Jul. 22, 2021

Gibs., which is derived by Lye from the Cimbr.

From The Lay of Havelok the Dane by Unknown

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