| ̷ ̷ˌ ̷ ̷+ noun
Etymology: International Scientific Vocabulary phenol + phthalein
: a white or yellowish white crystalline compound C 20 H 14 O 4 formed by condensation of phthalic anhydride and phenol and used in medicine as a laxative and in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by even weak acids — compare phthalein