phenolphthalein(redirected from Phthenolphthalein)
Also found in: Dictionary, Thesaurus, Encyclopedia.
a cathartic and pH indicator.
A hydrogen ion indicator obtained by the action of phenol on phthalic anhydride; formerly used as a laxative.
phenolphthalein(fē′nōl-thăl′ēn′, -thăl′ē-ĭn, -thā′lēn′, -thā′lē-ĭn)
A white or pale yellow crystalline powder, C20H14O4, used as an acid-base indicator, in making dyes, and formerly in medicine as an over-the-counter laxative.