# lye

/ˈɫaɪ/ (US) · /lˈaɪ/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/lye
Updated: 2026-05-30

## Definition

a very strong chemical used to make soap or to clean things. It is also used in some traditional foods, like pretzels, to give them a dark color and a soft crust.

For teachers: a strong alkaline solution, typically sodium hydroxide or potassium hydroxide, used in the saponification process to produce soap. It is also employed in industrial cleaning and food preparation to create a specific texture or appearance.

## Examples

- The chef brushed the dough with lye before baking the pretzels.
- Before modern detergents, people used lye mixed with animal fat to make their own soap for washing clothes.
- While highly effective for industrial degreasing, lye requires careful handling due to its caustic nature, as it can cause severe chemical burns if it comes into contact with skin or eyes.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.