English Reference

Word

methyl

US/ˈmɛθəɫ/

UK/mˈiːθaɪl/

Definition

n. a small group of atoms made of one carbon and three hydrogen atoms. It is a basic building block in chemistry that attaches to other molecules.

n. an alkyl radical derived from methane, consisting of one carbon atom covalently bonded to three hydrogen atoms. Often functions as a functional group within larger organic molecules.

Examples

“The scientist added a methyl group to the compound.”

“In biology, adding a methyl group to DNA can change how genes are expressed without altering the genetic code itself.”

“The synthesis of this specific hormone requires the transfer of a methyl group from a donor molecule, a process essential for maintaining metabolic balance within the cell.”

Examples

simple

“The scientist added a methyl group to the compound.”

contextual

“In biology, adding a methyl group to DNA can change how genes are expressed without altering the genetic code itself.”

complex

“The synthesis of this specific hormone requires the transfer of a methyl group from a donor molecule, a process essential for maintaining metabolic balance within the cell.”

Usage

Often used as a modifier before another noun, such as 'methyl group' or 'methyl alcohol'.

Real-World Examples

“The tank was at risk of exploding, potentially showering nearby neighbourhoods with methyl methacrylate (MMA), a skin and lung-irritating , external compound used in plastics production.”
BBC News · 15 Sept 2026
“The attachment of small chemical compounds—known as methyl groups—influences which genes are active and which remain silenced.”
Phys.org · 25 Aug 2026

Etymology

Borrowed from German Methyl; compare French méthyle. French chemists Jean-Baptiste Dumas and Eugene Peligot, after determining methanol's chemical structure, introduced "methylene" from the Ancient Greek μέθυ (méthu, “wine”) + ὕλη (húlē, “wood, material”) with the intention of highlighting its origins, "alcohol made from wood (substance)". The term "methyl" was derived in about 1840 by back-formation from "methylene", and was then applied to describe "methyl alcohol".

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

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C2 · Proficiency
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Frequent
Updated

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