Definition of "phenolphthalein" []

• A white or pale yellow crystalline powder, C20H14O4, used as an acid-base indicator, in making dyes, and formerly in medicine as a laxative. Because of its toxicity, it is no longer used in over-the-counter laxatives. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "And also another drug called phenolphthalein, which is -- I'll tell you it's not even a drug."
• "The first, a presumptive test such as phenolphthalein, offers clues about where blood may be."
• "The Food and Drug Administration said all lots of the supplement had been recalled because it contained the weight loss drug, sibutramine (Meridia), and phenolphthalein, a chemical that may cause cancer."