What does methylene mean?
Methylene is chiefly a chemical term for the divalent hydrocarbon group –CH₂–, a unit formed by removing two hydrogen atoms from methane. Because it has two available bonding sites, it commonly links other atoms or groups within a molecule. Methylene units occur in many hydrocarbons, synthetic polymers, solvents, and biological compounds, making the term important in organic chemistry, pharmacology, and materials science. Familiar compounds bearing the name include methylene chloride and methylene blue. The word also has an informal, chiefly North American use as a name for methamphetamine. That colloquial sense belongs to drug culture rather than scientific or medical usage. In formal writing, methylene usually refers either to the –CH₂– radical or, less precisely, to a methylene unit within a larger structure. It should not be confused with methyl, the one-bonded –CH₃– group, or with methine, the one-bonded –CH– unit.
A divalent hydrocarbon group, –CH₂–, capable of forming two bonds; more generally, a unit containing a carbon atom bonded to two hydrogen atoms.
"The reaction creates a new methylene linkage between the two molecular fragments."
A specialist organic-chemistry term; “methylene group” is usually more explicit than the unqualified noun.
Informally, methamphetamine.
"The suspect was charged after officers found what they believed to be methylene."
Informal and chiefly North American; avoid in formal, educational, or clinical contexts.
Rare; technical writing usually uses the plural form of a more explicit noun such as “methylene groups” instead.
"Several methylene units occur along the molecular chain."
Methylene is the versatile –CH₂– link found in plastics, solvents, medicines, and natural products—and informally, it is also a name for methamphetamine.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does methylene come from?
Methylene belongs to the methyl- family of chemical terminology. Its combining element comes through New Latin from Greek methuē, a term associated with wine or intoxicating drink and later with wood alcohol. The suffix -ylene denotes a divalent radical or group, and methylene specifically names the –CH₂– unit. The informal drug meaning arose separately through a shortened form of methamphetamine.
Related word forms
How methylene is actually used
The chemical senses are specialist and usually appear in organic chemistry, biochemistry, pharmaceuticals, and materials science. The informal use for methamphetamine is chiefly associated with North American drug slang and should not be used in formal or clinical writing.
Easily confused with methylene
A methyl group is –CH₃– and has one bonding site, whereas a methylene group is –CH₂– and has two bonding sites.
Methine refers to a –CH– unit with one hydrogen and one bonding site, while methylene refers to a –CH₂– unit with two bonding sites.