Standard Lemma guide

phenolphthalein

noun · 2 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.

  • Received-Pronunciation: /ˌfiː.nɒlˈ(f)θa.liːn/
  • Received-Pronunciation: /ˌfiː.nɒlˈ(f)θeɪ.liːn/
  • Southern-England: Recorded audio is listed in the source snapshot.
  • General-American: /ˌfi.nl̩ˈθæl.i.ɪn/
  • General-American: /ˌfi.nl̩ˈθæˌlin/
  • General-American: /ˌfi.nl̩ˈθeɪˌlin/
  • CMU ARPABET: F IY2 N AA0 L F TH EY1 L AH0 N Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
  • CMU ARPABET 2: F EH2 N AA0 L F TH EY1 L AH0 N Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.

1

noun

Meaning 1

A white or yellowish-white crystalline compound C20H14O4 used in medicine as a laxative and in analysis as an indicator because its solution is brilliant red in alkalies and is decolorized by acids.

Definition source: English Wiktionary via Wiktextract

Usage: countable, uncountable

Topics: chemistry, medicine, natural-sciences, organic-chemistry, pharmacology, physical-sciences, sciences

Examples

  • After transfering the acid to a 150-mL Erlenmeyer flask, add 60 mL of deionized water and 2 drops of phenolphthalein.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

2

noun

Meaning 2

a laxative used in many preparations under various trade names; also used as an acid-base indicator in titrations involving weak acids and strong bases because it is brilliant red at high alkalinity and colorless below pH 8

Definition source: Princeton WordNet 3.0

No example sentence was provided for this meaning.

Meaning relationships

Synonyms: none provided

Antonyms: none provided

Broader terms: laxative, acid-base indicator

History

Etymology

From phenol + phthalein.

Across languages

Translations

23 source translations are retained for this English entry.

  • Armenian: ֆենոլֆթալեին (fenolftʻalein) — Translations
  • Bengali: ফেনফথ্যালিন (phenphotthalin) — Translations
  • Chinese Cantonese: 酚酞 (fan1 taai3) — Translations
  • Chinese Mandarin: 酚酞 (fēntài) — Translations
  • Danish: fenolftalein — Translations
  • Dutch: fenolftaleïne — Translations
  • Finnish: fenoliftaleiini — Translations
  • French: phénolphtaléine — Translations
  • Georgian: ფენოლფთალეინი (penolptaleini) — Translations
  • German: Phenolphthalein — Translations
  • Irish: feanóltailéin — Translations
  • Japanese: フェノールフタレイン (fenōfutarein) — Translations
  • Kazakh: фенолфталейн (fenolftalein) — Translations
  • Korean: 페놀프탈레인 (penolpeutallein) — Translations
  • Māori: penopeirini — Translations
  • Persian: فنولفتالئین — Translations
  • Polish: fenoloftaleina — Translations
  • Portuguese: fenolftaleína — Translations
  • Romanian: fenolftaleină — Translations
  • Spanish: fenolftaleína — Translations
  • Telugu: ఫినాప్తలీన్ (phināptalīn) — Translations
  • Uzbek: fenolftalein — Translations
  • Vietnamese: phenolphtalein — Translations