# phthalein

> English word · Noun · IPA /ˈθeɪliːn/

## Definitions
1. Any of a range of lactones formed by the reaction of phenols with phthalic anhydride.

## Etymology
By surface analysis, phthal(ic) + -ein.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/phthalein