phenolphthalein

noun

phe·​nol·​phtha·​lein ˌfē-nᵊl-ˈtha-lē-ən How to pronounce phenolphthalein (audio)
-ˈtha-ˌlēn,
-ˈthā- How to pronounce phenolphthalein (audio)
: a white or yellowish-white crystalline compound C20H14O4 used in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by acids and in medicine as a laxative

Examples of phenolphthalein in a Sentence

Recent Examples on the Web Those ingredients included things like sibutramine, an appetite suppressant that was taken off the market due to the risk for strokes, as well as the laxative phenolphthalein. Sarah Jacoby, SELF, 17 Dec. 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'phenolphthalein.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

International Scientific Vocabulary phenol + phthalein any of various xanthene dyes, from phthalic acid

First Known Use

1875, in the meaning defined above

Time Traveler
The first known use of phenolphthalein was in 1875

Dictionary Entries Near phenolphthalein

Cite this Entry

“Phenolphthalein.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phenolphthalein. Accessed 18 Jul. 2024.

Kids Definition

phenolphthalein

noun
phe·​nol·​phtha·​lein ˌfēn-ᵊl-ˈthal-ē-ən How to pronounce phenolphthalein (audio) -ˈthal-ˌēn How to pronounce phenolphthalein (audio)
-ˈthāl-
: a white or yellowish white compound used as a laxative and as an acid-base indicator because its solution is brilliant red in alkalies and clear in acids

Medical Definition

phenolphthalein

noun
phe·​nol·​phtha·​lein ˌfēn-ᵊl-ˈthal-ē-ən How to pronounce phenolphthalein (audio) -ˈthal-ˌēn How to pronounce phenolphthalein (audio)
-ˈthāl-
: a white or yellowish white crystalline compound C20H14O4 that is used in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by acids and that is used in medicine as a laxative

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