thimerosal

noun

thi·​mer·​o·​sal thī-ˈmer-ə-ˌsal 

: a crystalline organic mercurial antiseptic C₉H₉HgNaO₂S used especially for its antifungal and bacteriostatic properties

Examples of thimerosal in a Sentence

Recent Examples on the Web

Notably, the word thimerosal does not appear in this week’s update from the CDC. —Benjamin Mazer, The Atlantic, 21 Nov. 2025

Many people confuse the controversy over the measles, mumps, and rubella (MMR) vaccine with that of thimerosal. —Lauren Gelman, Parents, 21 Nov. 2025

In one of its first actions, the new advisory committee called for the removal of the preservative thimerosal used in a small fraction of flu vaccines, even though safety concerns about it have also been debunked. —NPR, 20 Nov. 2025

Although studies show that thimerosal isn’t harmful — and doesn’t cause autism — manufacturers took the preservative out of routine pediatric vaccinations in 1999. —Liz Szabo, NBC news, 25 Oct. 2025

Word History

Etymology

probably from thi- + mercury + -o- + salicylate

First Known Use

1949, in the meaning defined above

Rhymes for thimerosal

• counterproposal
• disposal
• petrosal
• proposal
• serosal

Medical Definition

thimerosal

noun

thi·​mer·​o·​sal thī-ˈmer-ə-ˌsal 

: a crystalline organic mercurial antiseptic C₉H₉HgNaO₂S used especially for its antifungal and bacteriostatic properties see merthiolate