phenolphthalein

noun

phe·​nol·​phtha·​lein ˌfē-nᵊl-ˈtha-lē-ən 

-ˈtha-ˌlēn,

-ˈthā- 

: 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

Products containing the herb berberine offer only a few pounds of weight loss, while many dietary supplement weight loss products contain stimulants such as sibutramine and laxatives such as phenolphthalein, which increase the risk of heart attacks, strokes and cancer. —C. Michael White / The Conversation, Quartz, 21 Oct. 2024

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

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

Kids Definition

phenolphthalein

noun

phe·​nol·​phtha·​lein ˌfēn-ᵊl-ˈthal-ē-ən  -ˈthal-ˌēn 

-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  -ˈthal-ˌēn 

-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