# thiomersal

> English word · Noun

## Definitions
1. A compound, chemical formula C₉H₉HgNaO₂S, used as an antiseptic and antifungal agent, especially in vaccines.

## Etymology
From thio- + -mer- (“mercury-containing drug”) + -sal (“salicylic acid derivative”).

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