thimerosal

American

[thahy-mur-uh-sal, -mer-] / θaɪˈmɜr əˌsæl, -ˈmɛr- /

noun

Pharmacology.

a cream-colored, crystalline, water-soluble powder, C 9 H 9 HgNaO 2 S, used chiefly as an antiseptic.

thimerosal British

/ θaɪˈmɛrəˌsæl /

noun

a creamy white crystalline compound of mercury, used in solution as an antiseptic. Formula: C 9 H 9 HgNaO 2 S

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of thimerosal

1945–50; perhaps thi- + mer(cury) + -o- + sal(icylate)

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Manufacturers long ago removed thimerosal from childhood vaccines because of unfounded fears it contained mercury that could accumulate in the brain and unfounded fears about a relationship between mercury and autism.

From Los Angeles Times • Jun. 29, 2025

On Thursday, the group is scheduled to hear a presentation on the use of thimerosal in vaccines given by Lyn Redwood, a former leader of Children's Health Defense, an anti-vaccine group Kennedy used to run.

From BBC • Jun. 25, 2025

No study ever established a link between thimerosal and autism.

From Los Angeles Times • Apr. 1, 2025

He questioned the safety of thimerosal, a common vaccine preservative, advancing the debunked claim it could lead to autism.

From Science Magazine • Nov. 26, 2024

He wanted to reassure parents who were worried about the effects of a mercury-based preservative called thimerosal, found in some vaccines.

From BBC • Mar. 1, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023