methylmercury

noun

meth·​yl·​mer·​cury ˌme-thəl-ˈmər-kyə-rē 

-ˈmər-k(ə-)rē

: any of various toxic compounds of mercury containing the complex CH₃Hg− that often occur as pollutants which accumulate in living organisms (such as fish) especially in higher levels of a food chain

Examples of methylmercury in a Sentence

Recent Examples on the Web

At high levels, methylmercury (the type found in some fish) can be toxic. —Emily Kay Votruba, EverydayHealth.com, 27 June 2025

But those limits were set for methylmercury, the kind found in some fish, which is known to be toxic. —Meg Tirrell, CNN Money, 25 June 2025

Second, the federal guidelines on exposure limits for the toxic substance methylmercury came out about the same time as the Wakefield study’s publication. —Terri Levien, The Conversation, 25 June 2025

Microorganisms convert inorganic mercury in the environment into the compound methylmercury, which aquatic creatures inadvertently consume. —Tara Haelle, Scientific American, 25 June 2025

Word History

First Known Use

1915, in the meaning defined above

Rhymes for methylmercury

• mercury

Medical Definition

methylmercury

noun

meth·​yl·​mer·​cury

ˌmeth-əl-ˈmər-kyə-rē, British also ˌmē-ˌthīl-

plural methylmercuries

: any of various toxic compounds of mercury containing the complex CH₃Hg− that often occur as pollutants formed as industrial by-products or pesticide residues, tend to accumulate in living organisms (as fish) especially in higher levels of a food chain, are rapidly and easily absorbed through the human intestinal wall, and cause neurological dysfunction in humans see minamata disease